Upgrade V8 to version 4.9.385.28

https://chromium.googlesource.com/v8/v8/+/4.9.385.28

FPIIM-449

Change-Id: I4b2e74289d4bf3667f2f3dc8aa2e541f63e26eb4
diff --git a/src/debug/debug.js b/src/debug/debug.js
new file mode 100644
index 0000000..bc2c696
--- /dev/null
+++ b/src/debug/debug.js
@@ -0,0 +1,2612 @@
+// Copyright 2012 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+(function (global, utils) {
+"use strict";
+
+// ----------------------------------------------------------------------------
+// Imports
+
+var FrameMirror = global.FrameMirror;
+var GlobalArray = global.Array;
+var GlobalRegExp = global.RegExp;
+var IsNaN = global.isNaN;
+var JSONParse = global.JSON.parse;
+var JSONStringify = global.JSON.stringify;
+var LookupMirror = global.LookupMirror;
+var MakeError;
+var MakeTypeError;
+var MakeMirror = global.MakeMirror;
+var MakeMirrorSerializer = global.MakeMirrorSerializer;
+var MathMin = global.Math.min;
+var Mirror = global.Mirror;
+var MirrorType;
+var ParseInt = global.parseInt;
+var ValueMirror = global.ValueMirror;
+
+utils.Import(function(from) {
+  MakeError = from.MakeError;
+  MakeTypeError = from.MakeTypeError;
+  MirrorType = from.MirrorType;
+});
+
+//----------------------------------------------------------------------------
+
+// Default number of frames to include in the response to backtrace request.
+var kDefaultBacktraceLength = 10;
+
+var Debug = {};
+
+// Regular expression to skip "crud" at the beginning of a source line which is
+// not really code. Currently the regular expression matches whitespace and
+// comments.
+var sourceLineBeginningSkip = /^(?:\s*(?:\/\*.*?\*\/)*)*/;
+
+// Debug events which can occour in the V8 JavaScript engine. These originate
+// from the API include file debug.h.
+Debug.DebugEvent = { Break: 1,
+                     Exception: 2,
+                     NewFunction: 3,
+                     BeforeCompile: 4,
+                     AfterCompile: 5,
+                     CompileError: 6,
+                     PromiseEvent: 7,
+                     AsyncTaskEvent: 8 };
+
+// Types of exceptions that can be broken upon.
+Debug.ExceptionBreak = { Caught : 0,
+                         Uncaught: 1 };
+
+// The different types of steps.
+Debug.StepAction = { StepOut: 0,
+                     StepNext: 1,
+                     StepIn: 2,
+                     StepFrame: 3 };
+
+// The different types of scripts matching enum ScriptType in objects.h.
+Debug.ScriptType = { Native: 0,
+                     Extension: 1,
+                     Normal: 2 };
+
+// The different types of script compilations matching enum
+// Script::CompilationType in objects.h.
+Debug.ScriptCompilationType = { Host: 0,
+                                Eval: 1,
+                                JSON: 2 };
+
+// The different script break point types.
+Debug.ScriptBreakPointType = { ScriptId: 0,
+                               ScriptName: 1,
+                               ScriptRegExp: 2 };
+
+// The different types of breakpoint position alignments.
+// Must match BreakPositionAlignment in debug.h.
+Debug.BreakPositionAlignment = {
+  Statement: 0,
+  BreakPosition: 1
+};
+
+function ScriptTypeFlag(type) {
+  return (1 << type);
+}
+
+// Globals.
+var next_response_seq = 0;
+var next_break_point_number = 1;
+var break_points = [];
+var script_break_points = [];
+var debugger_flags = {
+  breakPointsActive: {
+    value: true,
+    getValue: function() { return this.value; },
+    setValue: function(value) {
+      this.value = !!value;
+      %SetBreakPointsActive(this.value);
+    }
+  },
+  breakOnCaughtException: {
+    getValue: function() { return Debug.isBreakOnException(); },
+    setValue: function(value) {
+      if (value) {
+        Debug.setBreakOnException();
+      } else {
+        Debug.clearBreakOnException();
+      }
+    }
+  },
+  breakOnUncaughtException: {
+    getValue: function() { return Debug.isBreakOnUncaughtException(); },
+    setValue: function(value) {
+      if (value) {
+        Debug.setBreakOnUncaughtException();
+      } else {
+        Debug.clearBreakOnUncaughtException();
+      }
+    }
+  },
+};
+
+
+// Create a new break point object and add it to the list of break points.
+function MakeBreakPoint(source_position, opt_script_break_point) {
+  var break_point = new BreakPoint(source_position, opt_script_break_point);
+  break_points.push(break_point);
+  return break_point;
+}
+
+
+// Object representing a break point.
+// NOTE: This object does not have a reference to the function having break
+// point as this would cause function not to be garbage collected when it is
+// not used any more. We do not want break points to keep functions alive.
+function BreakPoint(source_position, opt_script_break_point) {
+  this.source_position_ = source_position;
+  if (opt_script_break_point) {
+    this.script_break_point_ = opt_script_break_point;
+  } else {
+    this.number_ = next_break_point_number++;
+  }
+  this.hit_count_ = 0;
+  this.active_ = true;
+  this.condition_ = null;
+  this.ignoreCount_ = 0;
+}
+
+
+BreakPoint.prototype.number = function() {
+  return this.number_;
+};
+
+
+BreakPoint.prototype.func = function() {
+  return this.func_;
+};
+
+
+BreakPoint.prototype.source_position = function() {
+  return this.source_position_;
+};
+
+
+BreakPoint.prototype.hit_count = function() {
+  return this.hit_count_;
+};
+
+
+BreakPoint.prototype.active = function() {
+  if (this.script_break_point()) {
+    return this.script_break_point().active();
+  }
+  return this.active_;
+};
+
+
+BreakPoint.prototype.condition = function() {
+  if (this.script_break_point() && this.script_break_point().condition()) {
+    return this.script_break_point().condition();
+  }
+  return this.condition_;
+};
+
+
+BreakPoint.prototype.ignoreCount = function() {
+  return this.ignoreCount_;
+};
+
+
+BreakPoint.prototype.script_break_point = function() {
+  return this.script_break_point_;
+};
+
+
+BreakPoint.prototype.enable = function() {
+  this.active_ = true;
+};
+
+
+BreakPoint.prototype.disable = function() {
+  this.active_ = false;
+};
+
+
+BreakPoint.prototype.setCondition = function(condition) {
+  this.condition_ = condition;
+};
+
+
+BreakPoint.prototype.setIgnoreCount = function(ignoreCount) {
+  this.ignoreCount_ = ignoreCount;
+};
+
+
+BreakPoint.prototype.isTriggered = function(exec_state) {
+  // Break point not active - not triggered.
+  if (!this.active()) return false;
+
+  // Check for conditional break point.
+  if (this.condition()) {
+    // If break point has condition try to evaluate it in the top frame.
+    try {
+      var mirror = exec_state.frame(0).evaluate(this.condition());
+      // If no sensible mirror or non true value break point not triggered.
+      if (!(mirror instanceof ValueMirror) || !mirror.value_) {
+        return false;
+      }
+    } catch (e) {
+      // Exception evaluating condition counts as not triggered.
+      return false;
+    }
+  }
+
+  // Update the hit count.
+  this.hit_count_++;
+  if (this.script_break_point_) {
+    this.script_break_point_.hit_count_++;
+  }
+
+  // If the break point has an ignore count it is not triggered.
+  if (this.ignoreCount_ > 0) {
+    this.ignoreCount_--;
+    return false;
+  }
+
+  // Break point triggered.
+  return true;
+};
+
+
+// Function called from the runtime when a break point is hit. Returns true if
+// the break point is triggered and supposed to break execution.
+function IsBreakPointTriggered(break_id, break_point) {
+  return break_point.isTriggered(MakeExecutionState(break_id));
+}
+
+
+// Object representing a script break point. The script is referenced by its
+// script name or script id and the break point is represented as line and
+// column.
+function ScriptBreakPoint(type, script_id_or_name, opt_line, opt_column,
+                          opt_groupId, opt_position_alignment) {
+  this.type_ = type;
+  if (type == Debug.ScriptBreakPointType.ScriptId) {
+    this.script_id_ = script_id_or_name;
+  } else if (type == Debug.ScriptBreakPointType.ScriptName) {
+    this.script_name_ = script_id_or_name;
+  } else if (type == Debug.ScriptBreakPointType.ScriptRegExp) {
+    this.script_regexp_object_ = new GlobalRegExp(script_id_or_name);
+  } else {
+    throw MakeError(kDebugger, "Unexpected breakpoint type " + type);
+  }
+  this.line_ = opt_line || 0;
+  this.column_ = opt_column;
+  this.groupId_ = opt_groupId;
+  this.position_alignment_ = IS_UNDEFINED(opt_position_alignment)
+      ? Debug.BreakPositionAlignment.Statement : opt_position_alignment;
+  this.hit_count_ = 0;
+  this.active_ = true;
+  this.condition_ = null;
+  this.ignoreCount_ = 0;
+  this.break_points_ = [];
+}
+
+
+// Creates a clone of script breakpoint that is linked to another script.
+ScriptBreakPoint.prototype.cloneForOtherScript = function (other_script) {
+  var copy = new ScriptBreakPoint(Debug.ScriptBreakPointType.ScriptId,
+      other_script.id, this.line_, this.column_, this.groupId_,
+      this.position_alignment_);
+  copy.number_ = next_break_point_number++;
+  script_break_points.push(copy);
+
+  copy.hit_count_ = this.hit_count_;
+  copy.active_ = this.active_;
+  copy.condition_ = this.condition_;
+  copy.ignoreCount_ = this.ignoreCount_;
+  return copy;
+};
+
+
+ScriptBreakPoint.prototype.number = function() {
+  return this.number_;
+};
+
+
+ScriptBreakPoint.prototype.groupId = function() {
+  return this.groupId_;
+};
+
+
+ScriptBreakPoint.prototype.type = function() {
+  return this.type_;
+};
+
+
+ScriptBreakPoint.prototype.script_id = function() {
+  return this.script_id_;
+};
+
+
+ScriptBreakPoint.prototype.script_name = function() {
+  return this.script_name_;
+};
+
+
+ScriptBreakPoint.prototype.script_regexp_object = function() {
+  return this.script_regexp_object_;
+};
+
+
+ScriptBreakPoint.prototype.line = function() {
+  return this.line_;
+};
+
+
+ScriptBreakPoint.prototype.column = function() {
+  return this.column_;
+};
+
+
+ScriptBreakPoint.prototype.actual_locations = function() {
+  var locations = [];
+  for (var i = 0; i < this.break_points_.length; i++) {
+    locations.push(this.break_points_[i].actual_location);
+  }
+  return locations;
+};
+
+
+ScriptBreakPoint.prototype.update_positions = function(line, column) {
+  this.line_ = line;
+  this.column_ = column;
+};
+
+
+ScriptBreakPoint.prototype.hit_count = function() {
+  return this.hit_count_;
+};
+
+
+ScriptBreakPoint.prototype.active = function() {
+  return this.active_;
+};
+
+
+ScriptBreakPoint.prototype.condition = function() {
+  return this.condition_;
+};
+
+
+ScriptBreakPoint.prototype.ignoreCount = function() {
+  return this.ignoreCount_;
+};
+
+
+ScriptBreakPoint.prototype.enable = function() {
+  this.active_ = true;
+};
+
+
+ScriptBreakPoint.prototype.disable = function() {
+  this.active_ = false;
+};
+
+
+ScriptBreakPoint.prototype.setCondition = function(condition) {
+  this.condition_ = condition;
+};
+
+
+ScriptBreakPoint.prototype.setIgnoreCount = function(ignoreCount) {
+  this.ignoreCount_ = ignoreCount;
+
+  // Set ignore count on all break points created from this script break point.
+  for (var i = 0; i < this.break_points_.length; i++) {
+    this.break_points_[i].setIgnoreCount(ignoreCount);
+  }
+};
+
+
+// Check whether a script matches this script break point. Currently this is
+// only based on script name.
+ScriptBreakPoint.prototype.matchesScript = function(script) {
+  if (this.type_ == Debug.ScriptBreakPointType.ScriptId) {
+    return this.script_id_ == script.id;
+  } else {
+    // We might want to account columns here as well.
+    if (!(script.line_offset <= this.line_  &&
+          this.line_ < script.line_offset + script.lineCount())) {
+      return false;
+    }
+    if (this.type_ == Debug.ScriptBreakPointType.ScriptName) {
+      return this.script_name_ == script.nameOrSourceURL();
+    } else if (this.type_ == Debug.ScriptBreakPointType.ScriptRegExp) {
+      return this.script_regexp_object_.test(script.nameOrSourceURL());
+    } else {
+      throw MakeError(kDebugger, "Unexpected breakpoint type " + this.type_);
+    }
+  }
+};
+
+
+// Set the script break point in a script.
+ScriptBreakPoint.prototype.set = function (script) {
+  var column = this.column();
+  var line = this.line();
+  // If the column is undefined the break is on the line. To help locate the
+  // first piece of breakable code on the line try to find the column on the
+  // line which contains some source.
+  if (IS_UNDEFINED(column)) {
+    var source_line = script.sourceLine(this.line());
+
+    // Allocate array for caching the columns where the actual source starts.
+    if (!script.sourceColumnStart_) {
+      script.sourceColumnStart_ = new GlobalArray(script.lineCount());
+    }
+
+    // Fill cache if needed and get column where the actual source starts.
+    if (IS_UNDEFINED(script.sourceColumnStart_[line])) {
+      script.sourceColumnStart_[line] =
+          source_line.match(sourceLineBeginningSkip)[0].length;
+    }
+    column = script.sourceColumnStart_[line];
+  }
+
+  // Convert the line and column into an absolute position within the script.
+  var position = Debug.findScriptSourcePosition(script, this.line(), column);
+
+  // If the position is not found in the script (the script might be shorter
+  // than it used to be) just ignore it.
+  if (IS_NULL(position)) return;
+
+  // Create a break point object and set the break point.
+  var break_point = MakeBreakPoint(position, this);
+  break_point.setIgnoreCount(this.ignoreCount());
+  var actual_position = %SetScriptBreakPoint(script, position,
+                                             this.position_alignment_,
+                                             break_point);
+  if (IS_UNDEFINED(actual_position)) {
+    actual_position = position;
+  }
+  var actual_location = script.locationFromPosition(actual_position, true);
+  break_point.actual_location = { line: actual_location.line,
+                                  column: actual_location.column,
+                                  script_id: script.id };
+  this.break_points_.push(break_point);
+  return break_point;
+};
+
+
+// Clear all the break points created from this script break point
+ScriptBreakPoint.prototype.clear = function () {
+  var remaining_break_points = [];
+  for (var i = 0; i < break_points.length; i++) {
+    if (break_points[i].script_break_point() &&
+        break_points[i].script_break_point() === this) {
+      %ClearBreakPoint(break_points[i]);
+    } else {
+      remaining_break_points.push(break_points[i]);
+    }
+  }
+  break_points = remaining_break_points;
+  this.break_points_ = [];
+};
+
+
+// Function called from runtime when a new script is compiled to set any script
+// break points set in this script.
+function UpdateScriptBreakPoints(script) {
+  for (var i = 0; i < script_break_points.length; i++) {
+    var break_point = script_break_points[i];
+    if ((break_point.type() == Debug.ScriptBreakPointType.ScriptName ||
+         break_point.type() == Debug.ScriptBreakPointType.ScriptRegExp) &&
+        break_point.matchesScript(script)) {
+      break_point.set(script);
+    }
+  }
+}
+
+
+function GetScriptBreakPoints(script) {
+  var result = [];
+  for (var i = 0; i < script_break_points.length; i++) {
+    if (script_break_points[i].matchesScript(script)) {
+      result.push(script_break_points[i]);
+    }
+  }
+  return result;
+}
+
+
+Debug.setListener = function(listener, opt_data) {
+  if (!IS_FUNCTION(listener) && !IS_UNDEFINED(listener) && !IS_NULL(listener)) {
+    throw MakeTypeError(kDebuggerType);
+  }
+  %SetDebugEventListener(listener, opt_data);
+};
+
+
+Debug.breakLocations = function(f, opt_position_aligment) {
+  if (!IS_FUNCTION(f)) throw MakeTypeError(kDebuggerType);
+  var position_aligment = IS_UNDEFINED(opt_position_aligment)
+      ? Debug.BreakPositionAlignment.Statement : opt_position_aligment;
+  return %GetBreakLocations(f, position_aligment);
+};
+
+// Returns a Script object. If the parameter is a function the return value
+// is the script in which the function is defined. If the parameter is a string
+// the return value is the script for which the script name has that string
+// value.  If it is a regexp and there is a unique script whose name matches
+// we return that, otherwise undefined.
+Debug.findScript = function(func_or_script_name) {
+  if (IS_FUNCTION(func_or_script_name)) {
+    return %FunctionGetScript(func_or_script_name);
+  } else if (IS_REGEXP(func_or_script_name)) {
+    var scripts = Debug.scripts();
+    var last_result = null;
+    var result_count = 0;
+    for (var i in scripts) {
+      var script = scripts[i];
+      if (func_or_script_name.test(script.name)) {
+        last_result = script;
+        result_count++;
+      }
+    }
+    // Return the unique script matching the regexp.  If there are more
+    // than one we don't return a value since there is no good way to
+    // decide which one to return.  Returning a "random" one, say the
+    // first, would introduce nondeterminism (or something close to it)
+    // because the order is the heap iteration order.
+    if (result_count == 1) {
+      return last_result;
+    } else {
+      return UNDEFINED;
+    }
+  } else {
+    return %GetScript(func_or_script_name);
+  }
+};
+
+// Returns the script source. If the parameter is a function the return value
+// is the script source for the script in which the function is defined. If the
+// parameter is a string the return value is the script for which the script
+// name has that string value.
+Debug.scriptSource = function(func_or_script_name) {
+  return this.findScript(func_or_script_name).source;
+};
+
+
+Debug.source = function(f) {
+  if (!IS_FUNCTION(f)) throw MakeTypeError(kDebuggerType);
+  return %FunctionGetSourceCode(f);
+};
+
+
+Debug.sourcePosition = function(f) {
+  if (!IS_FUNCTION(f)) throw MakeTypeError(kDebuggerType);
+  return %FunctionGetScriptSourcePosition(f);
+};
+
+
+Debug.findFunctionSourceLocation = function(func, opt_line, opt_column) {
+  var script = %FunctionGetScript(func);
+  var script_offset = %FunctionGetScriptSourcePosition(func);
+  return script.locationFromLine(opt_line, opt_column, script_offset);
+};
+
+
+// Returns the character position in a script based on a line number and an
+// optional position within that line.
+Debug.findScriptSourcePosition = function(script, opt_line, opt_column) {
+  var location = script.locationFromLine(opt_line, opt_column);
+  return location ? location.position : null;
+};
+
+
+Debug.findBreakPoint = function(break_point_number, remove) {
+  var break_point;
+  for (var i = 0; i < break_points.length; i++) {
+    if (break_points[i].number() == break_point_number) {
+      break_point = break_points[i];
+      // Remove the break point from the list if requested.
+      if (remove) {
+        break_points.splice(i, 1);
+      }
+      break;
+    }
+  }
+  if (break_point) {
+    return break_point;
+  } else {
+    return this.findScriptBreakPoint(break_point_number, remove);
+  }
+};
+
+Debug.findBreakPointActualLocations = function(break_point_number) {
+  for (var i = 0; i < script_break_points.length; i++) {
+    if (script_break_points[i].number() == break_point_number) {
+      return script_break_points[i].actual_locations();
+    }
+  }
+  for (var i = 0; i < break_points.length; i++) {
+    if (break_points[i].number() == break_point_number) {
+      return [break_points[i].actual_location];
+    }
+  }
+  return [];
+};
+
+Debug.setBreakPoint = function(func, opt_line, opt_column, opt_condition) {
+  if (!IS_FUNCTION(func)) throw MakeTypeError(kDebuggerType);
+  // Break points in API functions are not supported.
+  if (%FunctionIsAPIFunction(func)) {
+    throw MakeError(kDebugger, 'Cannot set break point in native code.');
+  }
+  // Find source position relative to start of the function
+  var break_position =
+      this.findFunctionSourceLocation(func, opt_line, opt_column).position;
+  var source_position = break_position - this.sourcePosition(func);
+  // Find the script for the function.
+  var script = %FunctionGetScript(func);
+  // Break in builtin JavaScript code is not supported.
+  if (script.type == Debug.ScriptType.Native) {
+    throw MakeError(kDebugger, 'Cannot set break point in native code.');
+  }
+  // If the script for the function has a name convert this to a script break
+  // point.
+  if (script && script.id) {
+    // Adjust the source position to be script relative.
+    source_position += %FunctionGetScriptSourcePosition(func);
+    // Find line and column for the position in the script and set a script
+    // break point from that.
+    var location = script.locationFromPosition(source_position, false);
+    return this.setScriptBreakPointById(script.id,
+                                        location.line, location.column,
+                                        opt_condition);
+  } else {
+    // Set a break point directly on the function.
+    var break_point = MakeBreakPoint(source_position);
+    var actual_position =
+        %SetFunctionBreakPoint(func, source_position, break_point);
+    actual_position += this.sourcePosition(func);
+    var actual_location = script.locationFromPosition(actual_position, true);
+    break_point.actual_location = { line: actual_location.line,
+                                    column: actual_location.column,
+                                    script_id: script.id };
+    break_point.setCondition(opt_condition);
+    return break_point.number();
+  }
+};
+
+
+Debug.setBreakPointByScriptIdAndPosition = function(script_id, position,
+                                                    condition, enabled,
+                                                    opt_position_alignment)
+{
+  var break_point = MakeBreakPoint(position);
+  break_point.setCondition(condition);
+  if (!enabled) {
+    break_point.disable();
+  }
+  var scripts = this.scripts();
+  var position_alignment = IS_UNDEFINED(opt_position_alignment)
+      ? Debug.BreakPositionAlignment.Statement : opt_position_alignment;
+  for (var i = 0; i < scripts.length; i++) {
+    if (script_id == scripts[i].id) {
+      break_point.actual_position = %SetScriptBreakPoint(scripts[i], position,
+          position_alignment, break_point);
+      break;
+    }
+  }
+  return break_point;
+};
+
+
+Debug.enableBreakPoint = function(break_point_number) {
+  var break_point = this.findBreakPoint(break_point_number, false);
+  // Only enable if the breakpoint hasn't been deleted:
+  if (break_point) {
+    break_point.enable();
+  }
+};
+
+
+Debug.disableBreakPoint = function(break_point_number) {
+  var break_point = this.findBreakPoint(break_point_number, false);
+  // Only enable if the breakpoint hasn't been deleted:
+  if (break_point) {
+    break_point.disable();
+  }
+};
+
+
+Debug.changeBreakPointCondition = function(break_point_number, condition) {
+  var break_point = this.findBreakPoint(break_point_number, false);
+  break_point.setCondition(condition);
+};
+
+
+Debug.changeBreakPointIgnoreCount = function(break_point_number, ignoreCount) {
+  if (ignoreCount < 0) throw MakeError(kDebugger, 'Invalid argument');
+  var break_point = this.findBreakPoint(break_point_number, false);
+  break_point.setIgnoreCount(ignoreCount);
+};
+
+
+Debug.clearBreakPoint = function(break_point_number) {
+  var break_point = this.findBreakPoint(break_point_number, true);
+  if (break_point) {
+    return %ClearBreakPoint(break_point);
+  } else {
+    break_point = this.findScriptBreakPoint(break_point_number, true);
+    if (!break_point) throw MakeError(kDebugger, 'Invalid breakpoint');
+  }
+};
+
+
+Debug.clearAllBreakPoints = function() {
+  for (var i = 0; i < break_points.length; i++) {
+    var break_point = break_points[i];
+    %ClearBreakPoint(break_point);
+  }
+  break_points = [];
+};
+
+
+Debug.disableAllBreakPoints = function() {
+  // Disable all user defined breakpoints:
+  for (var i = 1; i < next_break_point_number; i++) {
+    Debug.disableBreakPoint(i);
+  }
+  // Disable all exception breakpoints:
+  %ChangeBreakOnException(Debug.ExceptionBreak.Caught, false);
+  %ChangeBreakOnException(Debug.ExceptionBreak.Uncaught, false);
+};
+
+
+Debug.findScriptBreakPoint = function(break_point_number, remove) {
+  var script_break_point;
+  for (var i = 0; i < script_break_points.length; i++) {
+    if (script_break_points[i].number() == break_point_number) {
+      script_break_point = script_break_points[i];
+      // Remove the break point from the list if requested.
+      if (remove) {
+        script_break_point.clear();
+        script_break_points.splice(i,1);
+      }
+      break;
+    }
+  }
+  return script_break_point;
+};
+
+
+// Sets a breakpoint in a script identified through id or name at the
+// specified source line and column within that line.
+Debug.setScriptBreakPoint = function(type, script_id_or_name,
+                                     opt_line, opt_column, opt_condition,
+                                     opt_groupId, opt_position_alignment) {
+  // Create script break point object.
+  var script_break_point =
+      new ScriptBreakPoint(type, script_id_or_name, opt_line, opt_column,
+                           opt_groupId, opt_position_alignment);
+
+  // Assign number to the new script break point and add it.
+  script_break_point.number_ = next_break_point_number++;
+  script_break_point.setCondition(opt_condition);
+  script_break_points.push(script_break_point);
+
+  // Run through all scripts to see if this script break point matches any
+  // loaded scripts.
+  var scripts = this.scripts();
+  for (var i = 0; i < scripts.length; i++) {
+    if (script_break_point.matchesScript(scripts[i])) {
+      script_break_point.set(scripts[i]);
+    }
+  }
+
+  return script_break_point.number();
+};
+
+
+Debug.setScriptBreakPointById = function(script_id,
+                                         opt_line, opt_column,
+                                         opt_condition, opt_groupId,
+                                         opt_position_alignment) {
+  return this.setScriptBreakPoint(Debug.ScriptBreakPointType.ScriptId,
+                                  script_id, opt_line, opt_column,
+                                  opt_condition, opt_groupId,
+                                  opt_position_alignment);
+};
+
+
+Debug.setScriptBreakPointByName = function(script_name,
+                                           opt_line, opt_column,
+                                           opt_condition, opt_groupId) {
+  return this.setScriptBreakPoint(Debug.ScriptBreakPointType.ScriptName,
+                                  script_name, opt_line, opt_column,
+                                  opt_condition, opt_groupId);
+};
+
+
+Debug.setScriptBreakPointByRegExp = function(script_regexp,
+                                             opt_line, opt_column,
+                                             opt_condition, opt_groupId) {
+  return this.setScriptBreakPoint(Debug.ScriptBreakPointType.ScriptRegExp,
+                                  script_regexp, opt_line, opt_column,
+                                  opt_condition, opt_groupId);
+};
+
+
+Debug.enableScriptBreakPoint = function(break_point_number) {
+  var script_break_point = this.findScriptBreakPoint(break_point_number, false);
+  script_break_point.enable();
+};
+
+
+Debug.disableScriptBreakPoint = function(break_point_number) {
+  var script_break_point = this.findScriptBreakPoint(break_point_number, false);
+  script_break_point.disable();
+};
+
+
+Debug.changeScriptBreakPointCondition = function(
+    break_point_number, condition) {
+  var script_break_point = this.findScriptBreakPoint(break_point_number, false);
+  script_break_point.setCondition(condition);
+};
+
+
+Debug.changeScriptBreakPointIgnoreCount = function(
+    break_point_number, ignoreCount) {
+  if (ignoreCount < 0) throw MakeError(kDebugger, 'Invalid argument');
+  var script_break_point = this.findScriptBreakPoint(break_point_number, false);
+  script_break_point.setIgnoreCount(ignoreCount);
+};
+
+
+Debug.scriptBreakPoints = function() {
+  return script_break_points;
+};
+
+
+Debug.clearStepping = function() {
+  %ClearStepping();
+};
+
+Debug.setBreakOnException = function() {
+  return %ChangeBreakOnException(Debug.ExceptionBreak.Caught, true);
+};
+
+Debug.clearBreakOnException = function() {
+  return %ChangeBreakOnException(Debug.ExceptionBreak.Caught, false);
+};
+
+Debug.isBreakOnException = function() {
+  return !!%IsBreakOnException(Debug.ExceptionBreak.Caught);
+};
+
+Debug.setBreakOnUncaughtException = function() {
+  return %ChangeBreakOnException(Debug.ExceptionBreak.Uncaught, true);
+};
+
+Debug.clearBreakOnUncaughtException = function() {
+  return %ChangeBreakOnException(Debug.ExceptionBreak.Uncaught, false);
+};
+
+Debug.isBreakOnUncaughtException = function() {
+  return !!%IsBreakOnException(Debug.ExceptionBreak.Uncaught);
+};
+
+Debug.showBreakPoints = function(f, full, opt_position_alignment) {
+  if (!IS_FUNCTION(f)) throw MakeError(kDebuggerType);
+  var source = full ? this.scriptSource(f) : this.source(f);
+  var offset = full ? this.sourcePosition(f) : 0;
+  var locations = this.breakLocations(f, opt_position_alignment);
+  if (!locations) return source;
+  locations.sort(function(x, y) { return x - y; });
+  var result = "";
+  var prev_pos = 0;
+  var pos;
+  for (var i = 0; i < locations.length; i++) {
+    pos = locations[i] - offset;
+    result += source.slice(prev_pos, pos);
+    result += "[B" + i + "]";
+    prev_pos = pos;
+  }
+  pos = source.length;
+  result += source.substring(prev_pos, pos);
+  return result;
+};
+
+
+// Get all the scripts currently loaded. Locating all the scripts is based on
+// scanning the heap.
+Debug.scripts = function() {
+  // Collect all scripts in the heap.
+  return %DebugGetLoadedScripts();
+};
+
+
+Debug.debuggerFlags = function() {
+  return debugger_flags;
+};
+
+Debug.MakeMirror = MakeMirror;
+
+function MakeExecutionState(break_id) {
+  return new ExecutionState(break_id);
+}
+
+function ExecutionState(break_id) {
+  this.break_id = break_id;
+  this.selected_frame = 0;
+}
+
+ExecutionState.prototype.prepareStep = function(action) {
+  if (action === Debug.StepAction.StepIn ||
+      action === Debug.StepAction.StepOut ||
+      action === Debug.StepAction.StepNext ||
+      action === Debug.StepAction.StepFrame) {
+    return %PrepareStep(this.break_id, action);
+  }
+  throw MakeTypeError(kDebuggerType);
+};
+
+ExecutionState.prototype.evaluateGlobal = function(source, disable_break,
+    opt_additional_context) {
+  return MakeMirror(%DebugEvaluateGlobal(this.break_id, source,
+                                         TO_BOOLEAN(disable_break),
+                                         opt_additional_context));
+};
+
+ExecutionState.prototype.frameCount = function() {
+  return %GetFrameCount(this.break_id);
+};
+
+ExecutionState.prototype.threadCount = function() {
+  return %GetThreadCount(this.break_id);
+};
+
+ExecutionState.prototype.frame = function(opt_index) {
+  // If no index supplied return the selected frame.
+  if (opt_index == null) opt_index = this.selected_frame;
+  if (opt_index < 0 || opt_index >= this.frameCount()) {
+    throw MakeTypeError(kDebuggerFrame);
+  }
+  return new FrameMirror(this.break_id, opt_index);
+};
+
+ExecutionState.prototype.setSelectedFrame = function(index) {
+  var i = TO_NUMBER(index);
+  if (i < 0 || i >= this.frameCount()) {
+    throw MakeTypeError(kDebuggerFrame);
+  }
+  this.selected_frame = i;
+};
+
+ExecutionState.prototype.selectedFrame = function() {
+  return this.selected_frame;
+};
+
+ExecutionState.prototype.debugCommandProcessor = function(opt_is_running) {
+  return new DebugCommandProcessor(this, opt_is_running);
+};
+
+
+function MakeBreakEvent(break_id, break_points_hit) {
+  return new BreakEvent(break_id, break_points_hit);
+}
+
+
+function BreakEvent(break_id, break_points_hit) {
+  this.frame_ = new FrameMirror(break_id, 0);
+  this.break_points_hit_ = break_points_hit;
+}
+
+
+BreakEvent.prototype.eventType = function() {
+  return Debug.DebugEvent.Break;
+};
+
+
+BreakEvent.prototype.func = function() {
+  return this.frame_.func();
+};
+
+
+BreakEvent.prototype.sourceLine = function() {
+  return this.frame_.sourceLine();
+};
+
+
+BreakEvent.prototype.sourceColumn = function() {
+  return this.frame_.sourceColumn();
+};
+
+
+BreakEvent.prototype.sourceLineText = function() {
+  return this.frame_.sourceLineText();
+};
+
+
+BreakEvent.prototype.breakPointsHit = function() {
+  return this.break_points_hit_;
+};
+
+
+BreakEvent.prototype.toJSONProtocol = function() {
+  var o = { seq: next_response_seq++,
+            type: "event",
+            event: "break",
+            body: { invocationText: this.frame_.invocationText() }
+          };
+
+  // Add script related information to the event if available.
+  var script = this.func().script();
+  if (script) {
+    o.body.sourceLine = this.sourceLine(),
+    o.body.sourceColumn = this.sourceColumn(),
+    o.body.sourceLineText = this.sourceLineText(),
+    o.body.script = MakeScriptObject_(script, false);
+  }
+
+  // Add an Array of break points hit if any.
+  if (this.breakPointsHit()) {
+    o.body.breakpoints = [];
+    for (var i = 0; i < this.breakPointsHit().length; i++) {
+      // Find the break point number. For break points originating from a
+      // script break point supply the script break point number.
+      var breakpoint = this.breakPointsHit()[i];
+      var script_break_point = breakpoint.script_break_point();
+      var number;
+      if (script_break_point) {
+        number = script_break_point.number();
+      } else {
+        number = breakpoint.number();
+      }
+      o.body.breakpoints.push(number);
+    }
+  }
+  return JSONStringify(ObjectToProtocolObject_(o));
+};
+
+
+function MakeExceptionEvent(break_id, exception, uncaught, promise) {
+  return new ExceptionEvent(break_id, exception, uncaught, promise);
+}
+
+
+function ExceptionEvent(break_id, exception, uncaught, promise) {
+  this.exec_state_ = new ExecutionState(break_id);
+  this.exception_ = exception;
+  this.uncaught_ = uncaught;
+  this.promise_ = promise;
+}
+
+
+ExceptionEvent.prototype.eventType = function() {
+  return Debug.DebugEvent.Exception;
+};
+
+
+ExceptionEvent.prototype.exception = function() {
+  return this.exception_;
+};
+
+
+ExceptionEvent.prototype.uncaught = function() {
+  return this.uncaught_;
+};
+
+
+ExceptionEvent.prototype.promise = function() {
+  return this.promise_;
+};
+
+
+ExceptionEvent.prototype.func = function() {
+  return this.exec_state_.frame(0).func();
+};
+
+
+ExceptionEvent.prototype.sourceLine = function() {
+  return this.exec_state_.frame(0).sourceLine();
+};
+
+
+ExceptionEvent.prototype.sourceColumn = function() {
+  return this.exec_state_.frame(0).sourceColumn();
+};
+
+
+ExceptionEvent.prototype.sourceLineText = function() {
+  return this.exec_state_.frame(0).sourceLineText();
+};
+
+
+ExceptionEvent.prototype.toJSONProtocol = function() {
+  var o = new ProtocolMessage();
+  o.event = "exception";
+  o.body = { uncaught: this.uncaught_,
+             exception: MakeMirror(this.exception_)
+           };
+
+  // Exceptions might happen whithout any JavaScript frames.
+  if (this.exec_state_.frameCount() > 0) {
+    o.body.sourceLine = this.sourceLine();
+    o.body.sourceColumn = this.sourceColumn();
+    o.body.sourceLineText = this.sourceLineText();
+
+    // Add script information to the event if available.
+    var script = this.func().script();
+    if (script) {
+      o.body.script = MakeScriptObject_(script, false);
+    }
+  } else {
+    o.body.sourceLine = -1;
+  }
+
+  return o.toJSONProtocol();
+};
+
+
+function MakeCompileEvent(script, type) {
+  return new CompileEvent(script, type);
+}
+
+
+function CompileEvent(script, type) {
+  this.script_ = MakeMirror(script);
+  this.type_ = type;
+}
+
+
+CompileEvent.prototype.eventType = function() {
+  return this.type_;
+};
+
+
+CompileEvent.prototype.script = function() {
+  return this.script_;
+};
+
+
+CompileEvent.prototype.toJSONProtocol = function() {
+  var o = new ProtocolMessage();
+  o.running = true;
+  switch (this.type_) {
+    case Debug.DebugEvent.BeforeCompile:
+      o.event = "beforeCompile";
+      break;
+    case Debug.DebugEvent.AfterCompile:
+      o.event = "afterCompile";
+      break;
+    case Debug.DebugEvent.CompileError:
+      o.event = "compileError";
+      break;
+  }
+  o.body = {};
+  o.body.script = this.script_;
+
+  return o.toJSONProtocol();
+};
+
+
+function MakeScriptObject_(script, include_source) {
+  var o = { id: script.id(),
+            name: script.name(),
+            lineOffset: script.lineOffset(),
+            columnOffset: script.columnOffset(),
+            lineCount: script.lineCount(),
+          };
+  if (!IS_UNDEFINED(script.data())) {
+    o.data = script.data();
+  }
+  if (include_source) {
+    o.source = script.source();
+  }
+  return o;
+}
+
+
+function MakePromiseEvent(event_data) {
+  return new PromiseEvent(event_data);
+}
+
+
+function PromiseEvent(event_data) {
+  this.promise_ = event_data.promise;
+  this.parentPromise_ = event_data.parentPromise;
+  this.status_ = event_data.status;
+  this.value_ = event_data.value;
+}
+
+
+PromiseEvent.prototype.promise = function() {
+  return MakeMirror(this.promise_);
+}
+
+
+PromiseEvent.prototype.parentPromise = function() {
+  return MakeMirror(this.parentPromise_);
+}
+
+
+PromiseEvent.prototype.status = function() {
+  return this.status_;
+}
+
+
+PromiseEvent.prototype.value = function() {
+  return MakeMirror(this.value_);
+}
+
+
+function MakeAsyncTaskEvent(event_data) {
+  return new AsyncTaskEvent(event_data);
+}
+
+
+function AsyncTaskEvent(event_data) {
+  this.type_ = event_data.type;
+  this.name_ = event_data.name;
+  this.id_ = event_data.id;
+}
+
+
+AsyncTaskEvent.prototype.type = function() {
+  return this.type_;
+}
+
+
+AsyncTaskEvent.prototype.name = function() {
+  return this.name_;
+}
+
+
+AsyncTaskEvent.prototype.id = function() {
+  return this.id_;
+}
+
+
+function DebugCommandProcessor(exec_state, opt_is_running) {
+  this.exec_state_ = exec_state;
+  this.running_ = opt_is_running || false;
+}
+
+
+DebugCommandProcessor.prototype.processDebugRequest = function (request) {
+  return this.processDebugJSONRequest(request);
+};
+
+
+function ProtocolMessage(request) {
+  // Update sequence number.
+  this.seq = next_response_seq++;
+
+  if (request) {
+    // If message is based on a request this is a response. Fill the initial
+    // response from the request.
+    this.type = 'response';
+    this.request_seq = request.seq;
+    this.command = request.command;
+  } else {
+    // If message is not based on a request it is a dabugger generated event.
+    this.type = 'event';
+  }
+  this.success = true;
+  // Handler may set this field to control debugger state.
+  this.running = UNDEFINED;
+}
+
+
+ProtocolMessage.prototype.setOption = function(name, value) {
+  if (!this.options_) {
+    this.options_ = {};
+  }
+  this.options_[name] = value;
+};
+
+
+ProtocolMessage.prototype.failed = function(message, opt_details) {
+  this.success = false;
+  this.message = message;
+  if (IS_OBJECT(opt_details)) {
+    this.error_details = opt_details;
+  }
+};
+
+
+ProtocolMessage.prototype.toJSONProtocol = function() {
+  // Encode the protocol header.
+  var json = {};
+  json.seq= this.seq;
+  if (this.request_seq) {
+    json.request_seq = this.request_seq;
+  }
+  json.type = this.type;
+  if (this.event) {
+    json.event = this.event;
+  }
+  if (this.command) {
+    json.command = this.command;
+  }
+  if (this.success) {
+    json.success = this.success;
+  } else {
+    json.success = false;
+  }
+  if (this.body) {
+    // Encode the body part.
+    var bodyJson;
+    var serializer = MakeMirrorSerializer(true, this.options_);
+    if (this.body instanceof Mirror) {
+      bodyJson = serializer.serializeValue(this.body);
+    } else if (this.body instanceof GlobalArray) {
+      bodyJson = [];
+      for (var i = 0; i < this.body.length; i++) {
+        if (this.body[i] instanceof Mirror) {
+          bodyJson.push(serializer.serializeValue(this.body[i]));
+        } else {
+          bodyJson.push(ObjectToProtocolObject_(this.body[i], serializer));
+        }
+      }
+    } else {
+      bodyJson = ObjectToProtocolObject_(this.body, serializer);
+    }
+    json.body = bodyJson;
+    json.refs = serializer.serializeReferencedObjects();
+  }
+  if (this.message) {
+    json.message = this.message;
+  }
+  if (this.error_details) {
+    json.error_details = this.error_details;
+  }
+  json.running = this.running;
+  return JSONStringify(json);
+};
+
+
+DebugCommandProcessor.prototype.createResponse = function(request) {
+  return new ProtocolMessage(request);
+};
+
+
+DebugCommandProcessor.prototype.processDebugJSONRequest = function(
+    json_request) {
+  var request;  // Current request.
+  var response;  // Generated response.
+  try {
+    try {
+      // Convert the JSON string to an object.
+      request = JSONParse(json_request);
+
+      // Create an initial response.
+      response = this.createResponse(request);
+
+      if (!request.type) {
+        throw MakeError(kDebugger, 'Type not specified');
+      }
+
+      if (request.type != 'request') {
+        throw MakeError(kDebugger,
+                        "Illegal type '" + request.type + "' in request");
+      }
+
+      if (!request.command) {
+        throw MakeError(kDebugger, 'Command not specified');
+      }
+
+      if (request.arguments) {
+        var args = request.arguments;
+        // TODO(yurys): remove request.arguments.compactFormat check once
+        // ChromeDevTools are switched to 'inlineRefs'
+        if (args.inlineRefs || args.compactFormat) {
+          response.setOption('inlineRefs', true);
+        }
+        if (!IS_UNDEFINED(args.maxStringLength)) {
+          response.setOption('maxStringLength', args.maxStringLength);
+        }
+      }
+
+      var key = request.command.toLowerCase();
+      var handler = DebugCommandProcessor.prototype.dispatch_[key];
+      if (IS_FUNCTION(handler)) {
+        %_Call(handler, this, request, response);
+      } else {
+        throw MakeError(kDebugger,
+                        'Unknown command "' + request.command + '" in request');
+      }
+    } catch (e) {
+      // If there is no response object created one (without command).
+      if (!response) {
+        response = this.createResponse();
+      }
+      response.success = false;
+      response.message = TO_STRING(e);
+    }
+
+    // Return the response as a JSON encoded string.
+    try {
+      if (!IS_UNDEFINED(response.running)) {
+        // Response controls running state.
+        this.running_ = response.running;
+      }
+      response.running = this.running_;
+      return response.toJSONProtocol();
+    } catch (e) {
+      // Failed to generate response - return generic error.
+      return '{"seq":' + response.seq + ',' +
+              '"request_seq":' + request.seq + ',' +
+              '"type":"response",' +
+              '"success":false,' +
+              '"message":"Internal error: ' + TO_STRING(e) + '"}';
+    }
+  } catch (e) {
+    // Failed in one of the catch blocks above - most generic error.
+    return '{"seq":0,"type":"response","success":false,"message":"Internal error"}';
+  }
+};
+
+
+DebugCommandProcessor.prototype.continueRequest_ = function(request, response) {
+  // Check for arguments for continue.
+  if (request.arguments) {
+    var action = Debug.StepAction.StepIn;
+
+    // Pull out arguments.
+    var stepaction = request.arguments.stepaction;
+
+    // Get the stepaction argument.
+    if (stepaction) {
+      if (stepaction == 'in') {
+        action = Debug.StepAction.StepIn;
+      } else if (stepaction == 'next') {
+        action = Debug.StepAction.StepNext;
+      } else if (stepaction == 'out') {
+        action = Debug.StepAction.StepOut;
+      } else {
+        throw MakeError(kDebugger,
+                        'Invalid stepaction argument "' + stepaction + '".');
+      }
+    }
+
+    // Set up the VM for stepping.
+    this.exec_state_.prepareStep(action);
+  }
+
+  // VM should be running after executing this request.
+  response.running = true;
+};
+
+
+DebugCommandProcessor.prototype.breakRequest_ = function(request, response) {
+  // Ignore as break command does not do anything when broken.
+};
+
+
+DebugCommandProcessor.prototype.setBreakPointRequest_ =
+    function(request, response) {
+  // Check for legal request.
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  // Pull out arguments.
+  var type = request.arguments.type;
+  var target = request.arguments.target;
+  var line = request.arguments.line;
+  var column = request.arguments.column;
+  var enabled = IS_UNDEFINED(request.arguments.enabled) ?
+      true : request.arguments.enabled;
+  var condition = request.arguments.condition;
+  var ignoreCount = request.arguments.ignoreCount;
+  var groupId = request.arguments.groupId;
+
+  // Check for legal arguments.
+  if (!type || IS_UNDEFINED(target)) {
+    response.failed('Missing argument "type" or "target"');
+    return;
+  }
+
+  // Either function or script break point.
+  var break_point_number;
+  if (type == 'function') {
+    // Handle function break point.
+    if (!IS_STRING(target)) {
+      response.failed('Argument "target" is not a string value');
+      return;
+    }
+    var f;
+    try {
+      // Find the function through a global evaluate.
+      f = this.exec_state_.evaluateGlobal(target).value();
+    } catch (e) {
+      response.failed('Error: "' + TO_STRING(e) +
+                      '" evaluating "' + target + '"');
+      return;
+    }
+    if (!IS_FUNCTION(f)) {
+      response.failed('"' + target + '" does not evaluate to a function');
+      return;
+    }
+
+    // Set function break point.
+    break_point_number = Debug.setBreakPoint(f, line, column, condition);
+  } else if (type == 'handle') {
+    // Find the object pointed by the specified handle.
+    var handle = ParseInt(target, 10);
+    var mirror = LookupMirror(handle);
+    if (!mirror) {
+      return response.failed('Object #' + handle + '# not found');
+    }
+    if (!mirror.isFunction()) {
+      return response.failed('Object #' + handle + '# is not a function');
+    }
+
+    // Set function break point.
+    break_point_number = Debug.setBreakPoint(mirror.value(),
+                                             line, column, condition);
+  } else if (type == 'script') {
+    // set script break point.
+    break_point_number =
+        Debug.setScriptBreakPointByName(target, line, column, condition,
+                                        groupId);
+  } else if (type == 'scriptId') {
+    break_point_number =
+        Debug.setScriptBreakPointById(target, line, column, condition, groupId);
+  } else if (type == 'scriptRegExp') {
+    break_point_number =
+        Debug.setScriptBreakPointByRegExp(target, line, column, condition,
+                                          groupId);
+  } else {
+    response.failed('Illegal type "' + type + '"');
+    return;
+  }
+
+  // Set additional break point properties.
+  var break_point = Debug.findBreakPoint(break_point_number);
+  if (ignoreCount) {
+    Debug.changeBreakPointIgnoreCount(break_point_number, ignoreCount);
+  }
+  if (!enabled) {
+    Debug.disableBreakPoint(break_point_number);
+  }
+
+  // Add the break point number to the response.
+  response.body = { type: type,
+                    breakpoint: break_point_number };
+
+  // Add break point information to the response.
+  if (break_point instanceof ScriptBreakPoint) {
+    if (break_point.type() == Debug.ScriptBreakPointType.ScriptId) {
+      response.body.type = 'scriptId';
+      response.body.script_id = break_point.script_id();
+    } else if (break_point.type() == Debug.ScriptBreakPointType.ScriptName) {
+      response.body.type = 'scriptName';
+      response.body.script_name = break_point.script_name();
+    } else if (break_point.type() == Debug.ScriptBreakPointType.ScriptRegExp) {
+      response.body.type = 'scriptRegExp';
+      response.body.script_regexp = break_point.script_regexp_object().source;
+    } else {
+      throw MakeError(kDebugger,
+                      "Unexpected breakpoint type: " + break_point.type());
+    }
+    response.body.line = break_point.line();
+    response.body.column = break_point.column();
+    response.body.actual_locations = break_point.actual_locations();
+  } else {
+    response.body.type = 'function';
+    response.body.actual_locations = [break_point.actual_location];
+  }
+};
+
+
+DebugCommandProcessor.prototype.changeBreakPointRequest_ = function(
+    request, response) {
+  // Check for legal request.
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  // Pull out arguments.
+  var break_point = TO_NUMBER(request.arguments.breakpoint);
+  var enabled = request.arguments.enabled;
+  var condition = request.arguments.condition;
+  var ignoreCount = request.arguments.ignoreCount;
+
+  // Check for legal arguments.
+  if (!break_point) {
+    response.failed('Missing argument "breakpoint"');
+    return;
+  }
+
+  // Change enabled state if supplied.
+  if (!IS_UNDEFINED(enabled)) {
+    if (enabled) {
+      Debug.enableBreakPoint(break_point);
+    } else {
+      Debug.disableBreakPoint(break_point);
+    }
+  }
+
+  // Change condition if supplied
+  if (!IS_UNDEFINED(condition)) {
+    Debug.changeBreakPointCondition(break_point, condition);
+  }
+
+  // Change ignore count if supplied
+  if (!IS_UNDEFINED(ignoreCount)) {
+    Debug.changeBreakPointIgnoreCount(break_point, ignoreCount);
+  }
+};
+
+
+DebugCommandProcessor.prototype.clearBreakPointGroupRequest_ = function(
+    request, response) {
+  // Check for legal request.
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  // Pull out arguments.
+  var group_id = request.arguments.groupId;
+
+  // Check for legal arguments.
+  if (!group_id) {
+    response.failed('Missing argument "groupId"');
+    return;
+  }
+
+  var cleared_break_points = [];
+  var new_script_break_points = [];
+  for (var i = 0; i < script_break_points.length; i++) {
+    var next_break_point = script_break_points[i];
+    if (next_break_point.groupId() == group_id) {
+      cleared_break_points.push(next_break_point.number());
+      next_break_point.clear();
+    } else {
+      new_script_break_points.push(next_break_point);
+    }
+  }
+  script_break_points = new_script_break_points;
+
+  // Add the cleared break point numbers to the response.
+  response.body = { breakpoints: cleared_break_points };
+};
+
+
+DebugCommandProcessor.prototype.clearBreakPointRequest_ = function(
+    request, response) {
+  // Check for legal request.
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  // Pull out arguments.
+  var break_point = TO_NUMBER(request.arguments.breakpoint);
+
+  // Check for legal arguments.
+  if (!break_point) {
+    response.failed('Missing argument "breakpoint"');
+    return;
+  }
+
+  // Clear break point.
+  Debug.clearBreakPoint(break_point);
+
+  // Add the cleared break point number to the response.
+  response.body = { breakpoint: break_point };
+};
+
+
+DebugCommandProcessor.prototype.listBreakpointsRequest_ = function(
+    request, response) {
+  var array = [];
+  for (var i = 0; i < script_break_points.length; i++) {
+    var break_point = script_break_points[i];
+
+    var description = {
+      number: break_point.number(),
+      line: break_point.line(),
+      column: break_point.column(),
+      groupId: break_point.groupId(),
+      hit_count: break_point.hit_count(),
+      active: break_point.active(),
+      condition: break_point.condition(),
+      ignoreCount: break_point.ignoreCount(),
+      actual_locations: break_point.actual_locations()
+    };
+
+    if (break_point.type() == Debug.ScriptBreakPointType.ScriptId) {
+      description.type = 'scriptId';
+      description.script_id = break_point.script_id();
+    } else if (break_point.type() == Debug.ScriptBreakPointType.ScriptName) {
+      description.type = 'scriptName';
+      description.script_name = break_point.script_name();
+    } else if (break_point.type() == Debug.ScriptBreakPointType.ScriptRegExp) {
+      description.type = 'scriptRegExp';
+      description.script_regexp = break_point.script_regexp_object().source;
+    } else {
+      throw MakeError(kDebugger,
+                      "Unexpected breakpoint type: " + break_point.type());
+    }
+    array.push(description);
+  }
+
+  response.body = {
+    breakpoints: array,
+    breakOnExceptions: Debug.isBreakOnException(),
+    breakOnUncaughtExceptions: Debug.isBreakOnUncaughtException()
+  };
+};
+
+
+DebugCommandProcessor.prototype.disconnectRequest_ =
+    function(request, response) {
+  Debug.disableAllBreakPoints();
+  this.continueRequest_(request, response);
+};
+
+
+DebugCommandProcessor.prototype.setExceptionBreakRequest_ =
+    function(request, response) {
+  // Check for legal request.
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  // Pull out and check the 'type' argument:
+  var type = request.arguments.type;
+  if (!type) {
+    response.failed('Missing argument "type"');
+    return;
+  }
+
+  // Initialize the default value of enable:
+  var enabled;
+  if (type == 'all') {
+    enabled = !Debug.isBreakOnException();
+  } else if (type == 'uncaught') {
+    enabled = !Debug.isBreakOnUncaughtException();
+  }
+
+  // Pull out and check the 'enabled' argument if present:
+  if (!IS_UNDEFINED(request.arguments.enabled)) {
+    enabled = request.arguments.enabled;
+    if ((enabled != true) && (enabled != false)) {
+      response.failed('Illegal value for "enabled":"' + enabled + '"');
+    }
+  }
+
+  // Now set the exception break state:
+  if (type == 'all') {
+    %ChangeBreakOnException(Debug.ExceptionBreak.Caught, enabled);
+  } else if (type == 'uncaught') {
+    %ChangeBreakOnException(Debug.ExceptionBreak.Uncaught, enabled);
+  } else {
+    response.failed('Unknown "type":"' + type + '"');
+  }
+
+  // Add the cleared break point number to the response.
+  response.body = { 'type': type, 'enabled': enabled };
+};
+
+
+DebugCommandProcessor.prototype.backtraceRequest_ = function(
+    request, response) {
+  // Get the number of frames.
+  var total_frames = this.exec_state_.frameCount();
+
+  // Create simple response if there are no frames.
+  if (total_frames == 0) {
+    response.body = {
+      totalFrames: total_frames
+    };
+    return;
+  }
+
+  // Default frame range to include in backtrace.
+  var from_index = 0;
+  var to_index = kDefaultBacktraceLength;
+
+  // Get the range from the arguments.
+  if (request.arguments) {
+    if (request.arguments.fromFrame) {
+      from_index = request.arguments.fromFrame;
+    }
+    if (request.arguments.toFrame) {
+      to_index = request.arguments.toFrame;
+    }
+    if (request.arguments.bottom) {
+      var tmp_index = total_frames - from_index;
+      from_index = total_frames - to_index;
+      to_index = tmp_index;
+    }
+    if (from_index < 0 || to_index < 0) {
+      return response.failed('Invalid frame number');
+    }
+  }
+
+  // Adjust the index.
+  to_index = MathMin(total_frames, to_index);
+
+  if (to_index <= from_index) {
+    var error = 'Invalid frame range';
+    return response.failed(error);
+  }
+
+  // Create the response body.
+  var frames = [];
+  for (var i = from_index; i < to_index; i++) {
+    frames.push(this.exec_state_.frame(i));
+  }
+  response.body = {
+    fromFrame: from_index,
+    toFrame: to_index,
+    totalFrames: total_frames,
+    frames: frames
+  };
+};
+
+
+DebugCommandProcessor.prototype.frameRequest_ = function(request, response) {
+  // No frames no source.
+  if (this.exec_state_.frameCount() == 0) {
+    return response.failed('No frames');
+  }
+
+  // With no arguments just keep the selected frame.
+  if (request.arguments) {
+    var index = request.arguments.number;
+    if (index < 0 || this.exec_state_.frameCount() <= index) {
+      return response.failed('Invalid frame number');
+    }
+
+    this.exec_state_.setSelectedFrame(request.arguments.number);
+  }
+  response.body = this.exec_state_.frame();
+};
+
+
+DebugCommandProcessor.prototype.resolveFrameFromScopeDescription_ =
+    function(scope_description) {
+  // Get the frame for which the scope or scopes are requested.
+  // With no frameNumber argument use the currently selected frame.
+  if (scope_description && !IS_UNDEFINED(scope_description.frameNumber)) {
+    var frame_index = scope_description.frameNumber;
+    if (frame_index < 0 || this.exec_state_.frameCount() <= frame_index) {
+      throw MakeTypeError(kDebuggerFrame);
+    }
+    return this.exec_state_.frame(frame_index);
+  } else {
+    return this.exec_state_.frame();
+  }
+};
+
+
+// Gets scope host object from request. It is either a function
+// ('functionHandle' argument must be specified) or a stack frame
+// ('frameNumber' may be specified and the current frame is taken by default).
+DebugCommandProcessor.prototype.resolveScopeHolder_ =
+    function(scope_description) {
+  if (scope_description && "functionHandle" in scope_description) {
+    if (!IS_NUMBER(scope_description.functionHandle)) {
+      throw MakeError(kDebugger, 'Function handle must be a number');
+    }
+    var function_mirror = LookupMirror(scope_description.functionHandle);
+    if (!function_mirror) {
+      throw MakeError(kDebugger, 'Failed to find function object by handle');
+    }
+    if (!function_mirror.isFunction()) {
+      throw MakeError(kDebugger,
+                      'Value of non-function type is found by handle');
+    }
+    return function_mirror;
+  } else {
+    // No frames no scopes.
+    if (this.exec_state_.frameCount() == 0) {
+      throw MakeError(kDebugger, 'No scopes');
+    }
+
+    // Get the frame for which the scopes are requested.
+    var frame = this.resolveFrameFromScopeDescription_(scope_description);
+    return frame;
+  }
+}
+
+
+DebugCommandProcessor.prototype.scopesRequest_ = function(request, response) {
+  var scope_holder = this.resolveScopeHolder_(request.arguments);
+
+  // Fill all scopes for this frame or function.
+  var total_scopes = scope_holder.scopeCount();
+  var scopes = [];
+  for (var i = 0; i < total_scopes; i++) {
+    scopes.push(scope_holder.scope(i));
+  }
+  response.body = {
+    fromScope: 0,
+    toScope: total_scopes,
+    totalScopes: total_scopes,
+    scopes: scopes
+  };
+};
+
+
+DebugCommandProcessor.prototype.scopeRequest_ = function(request, response) {
+  // Get the frame or function for which the scope is requested.
+  var scope_holder = this.resolveScopeHolder_(request.arguments);
+
+  // With no scope argument just return top scope.
+  var scope_index = 0;
+  if (request.arguments && !IS_UNDEFINED(request.arguments.number)) {
+    scope_index = TO_NUMBER(request.arguments.number);
+    if (scope_index < 0 || scope_holder.scopeCount() <= scope_index) {
+      return response.failed('Invalid scope number');
+    }
+  }
+
+  response.body = scope_holder.scope(scope_index);
+};
+
+
+// Reads value from protocol description. Description may be in form of type
+// (for singletons), raw value (primitive types supported in JSON),
+// string value description plus type (for primitive values) or handle id.
+// Returns raw value or throws exception.
+DebugCommandProcessor.resolveValue_ = function(value_description) {
+  if ("handle" in value_description) {
+    var value_mirror = LookupMirror(value_description.handle);
+    if (!value_mirror) {
+      throw MakeError(kDebugger, "Failed to resolve value by handle, ' #" +
+                                 value_description.handle + "# not found");
+    }
+    return value_mirror.value();
+  } else if ("stringDescription" in value_description) {
+    if (value_description.type == MirrorType.BOOLEAN_TYPE) {
+      return TO_BOOLEAN(value_description.stringDescription);
+    } else if (value_description.type == MirrorType.NUMBER_TYPE) {
+      return TO_NUMBER(value_description.stringDescription);
+    } if (value_description.type == MirrorType.STRING_TYPE) {
+      return TO_STRING(value_description.stringDescription);
+    } else {
+      throw MakeError(kDebugger, "Unknown type");
+    }
+  } else if ("value" in value_description) {
+    return value_description.value;
+  } else if (value_description.type == MirrorType.UNDEFINED_TYPE) {
+    return UNDEFINED;
+  } else if (value_description.type == MirrorType.NULL_TYPE) {
+    return null;
+  } else {
+    throw MakeError(kDebugger, "Failed to parse value description");
+  }
+};
+
+
+DebugCommandProcessor.prototype.setVariableValueRequest_ =
+    function(request, response) {
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  if (IS_UNDEFINED(request.arguments.name)) {
+    response.failed('Missing variable name');
+  }
+  var variable_name = request.arguments.name;
+
+  var scope_description = request.arguments.scope;
+
+  // Get the frame or function for which the scope is requested.
+  var scope_holder = this.resolveScopeHolder_(scope_description);
+
+  if (IS_UNDEFINED(scope_description.number)) {
+    response.failed('Missing scope number');
+  }
+  var scope_index = TO_NUMBER(scope_description.number);
+
+  var scope = scope_holder.scope(scope_index);
+
+  var new_value =
+      DebugCommandProcessor.resolveValue_(request.arguments.newValue);
+
+  scope.setVariableValue(variable_name, new_value);
+
+  var new_value_mirror = MakeMirror(new_value);
+
+  response.body = {
+    newValue: new_value_mirror
+  };
+};
+
+
+DebugCommandProcessor.prototype.evaluateRequest_ = function(request, response) {
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+
+  // Pull out arguments.
+  var expression = request.arguments.expression;
+  var frame = request.arguments.frame;
+  var global = request.arguments.global;
+  var disable_break = request.arguments.disable_break;
+  var additional_context = request.arguments.additional_context;
+
+  // The expression argument could be an integer so we convert it to a
+  // string.
+  try {
+    expression = TO_STRING(expression);
+  } catch(e) {
+    return response.failed('Failed to convert expression argument to string');
+  }
+
+  // Check for legal arguments.
+  if (!IS_UNDEFINED(frame) && global) {
+    return response.failed('Arguments "frame" and "global" are exclusive');
+  }
+
+  var additional_context_object;
+  if (additional_context) {
+    additional_context_object = {};
+    for (var i = 0; i < additional_context.length; i++) {
+      var mapping = additional_context[i];
+
+      if (!IS_STRING(mapping.name)) {
+        return response.failed("Context element #" + i +
+            " doesn't contain name:string property");
+      }
+
+      var raw_value = DebugCommandProcessor.resolveValue_(mapping);
+      additional_context_object[mapping.name] = raw_value;
+    }
+  }
+
+  // Global evaluate.
+  if (global) {
+    // Evaluate in the native context.
+    response.body = this.exec_state_.evaluateGlobal(
+        expression, TO_BOOLEAN(disable_break), additional_context_object);
+    return;
+  }
+
+  // Default value for disable_break is true.
+  if (IS_UNDEFINED(disable_break)) {
+    disable_break = true;
+  }
+
+  // No frames no evaluate in frame.
+  if (this.exec_state_.frameCount() == 0) {
+    return response.failed('No frames');
+  }
+
+  // Check whether a frame was specified.
+  if (!IS_UNDEFINED(frame)) {
+    var frame_number = TO_NUMBER(frame);
+    if (frame_number < 0 || frame_number >= this.exec_state_.frameCount()) {
+      return response.failed('Invalid frame "' + frame + '"');
+    }
+    // Evaluate in the specified frame.
+    response.body = this.exec_state_.frame(frame_number).evaluate(
+        expression, TO_BOOLEAN(disable_break), additional_context_object);
+    return;
+  } else {
+    // Evaluate in the selected frame.
+    response.body = this.exec_state_.frame().evaluate(
+        expression, TO_BOOLEAN(disable_break), additional_context_object);
+    return;
+  }
+};
+
+
+DebugCommandProcessor.prototype.lookupRequest_ = function(request, response) {
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+
+  // Pull out arguments.
+  var handles = request.arguments.handles;
+
+  // Check for legal arguments.
+  if (IS_UNDEFINED(handles)) {
+    return response.failed('Argument "handles" missing');
+  }
+
+  // Set 'includeSource' option for script lookup.
+  if (!IS_UNDEFINED(request.arguments.includeSource)) {
+    var includeSource = TO_BOOLEAN(request.arguments.includeSource);
+    response.setOption('includeSource', includeSource);
+  }
+
+  // Lookup handles.
+  var mirrors = {};
+  for (var i = 0; i < handles.length; i++) {
+    var handle = handles[i];
+    var mirror = LookupMirror(handle);
+    if (!mirror) {
+      return response.failed('Object #' + handle + '# not found');
+    }
+    mirrors[handle] = mirror;
+  }
+  response.body = mirrors;
+};
+
+
+DebugCommandProcessor.prototype.referencesRequest_ =
+    function(request, response) {
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+
+  // Pull out arguments.
+  var type = request.arguments.type;
+  var handle = request.arguments.handle;
+
+  // Check for legal arguments.
+  if (IS_UNDEFINED(type)) {
+    return response.failed('Argument "type" missing');
+  }
+  if (IS_UNDEFINED(handle)) {
+    return response.failed('Argument "handle" missing');
+  }
+  if (type != 'referencedBy' && type != 'constructedBy') {
+    return response.failed('Invalid type "' + type + '"');
+  }
+
+  // Lookup handle and return objects with references the object.
+  var mirror = LookupMirror(handle);
+  if (mirror) {
+    if (type == 'referencedBy') {
+      response.body = mirror.referencedBy();
+    } else {
+      response.body = mirror.constructedBy();
+    }
+  } else {
+    return response.failed('Object #' + handle + '# not found');
+  }
+};
+
+
+DebugCommandProcessor.prototype.sourceRequest_ = function(request, response) {
+  // No frames no source.
+  if (this.exec_state_.frameCount() == 0) {
+    return response.failed('No source');
+  }
+
+  var from_line;
+  var to_line;
+  var frame = this.exec_state_.frame();
+  if (request.arguments) {
+    // Pull out arguments.
+    from_line = request.arguments.fromLine;
+    to_line = request.arguments.toLine;
+
+    if (!IS_UNDEFINED(request.arguments.frame)) {
+      var frame_number = TO_NUMBER(request.arguments.frame);
+      if (frame_number < 0 || frame_number >= this.exec_state_.frameCount()) {
+        return response.failed('Invalid frame "' + frame + '"');
+      }
+      frame = this.exec_state_.frame(frame_number);
+    }
+  }
+
+  // Get the script selected.
+  var script = frame.func().script();
+  if (!script) {
+    return response.failed('No source');
+  }
+
+  // Get the source slice and fill it into the response.
+  var slice = script.sourceSlice(from_line, to_line);
+  if (!slice) {
+    return response.failed('Invalid line interval');
+  }
+  response.body = {};
+  response.body.source = slice.sourceText();
+  response.body.fromLine = slice.from_line;
+  response.body.toLine = slice.to_line;
+  response.body.fromPosition = slice.from_position;
+  response.body.toPosition = slice.to_position;
+  response.body.totalLines = script.lineCount();
+};
+
+
+DebugCommandProcessor.prototype.scriptsRequest_ = function(request, response) {
+  var types = ScriptTypeFlag(Debug.ScriptType.Normal);
+  var includeSource = false;
+  var idsToInclude = null;
+  if (request.arguments) {
+    // Pull out arguments.
+    if (!IS_UNDEFINED(request.arguments.types)) {
+      types = TO_NUMBER(request.arguments.types);
+      if (IsNaN(types) || types < 0) {
+        return response.failed('Invalid types "' +
+                               request.arguments.types + '"');
+      }
+    }
+
+    if (!IS_UNDEFINED(request.arguments.includeSource)) {
+      includeSource = TO_BOOLEAN(request.arguments.includeSource);
+      response.setOption('includeSource', includeSource);
+    }
+
+    if (IS_ARRAY(request.arguments.ids)) {
+      idsToInclude = {};
+      var ids = request.arguments.ids;
+      for (var i = 0; i < ids.length; i++) {
+        idsToInclude[ids[i]] = true;
+      }
+    }
+
+    var filterStr = null;
+    var filterNum = null;
+    if (!IS_UNDEFINED(request.arguments.filter)) {
+      var num = TO_NUMBER(request.arguments.filter);
+      if (!IsNaN(num)) {
+        filterNum = num;
+      }
+      filterStr = request.arguments.filter;
+    }
+  }
+
+  // Collect all scripts in the heap.
+  var scripts = %DebugGetLoadedScripts();
+
+  response.body = [];
+
+  for (var i = 0; i < scripts.length; i++) {
+    if (idsToInclude && !idsToInclude[scripts[i].id]) {
+      continue;
+    }
+    if (filterStr || filterNum) {
+      var script = scripts[i];
+      var found = false;
+      if (filterNum && !found) {
+        if (script.id && script.id === filterNum) {
+          found = true;
+        }
+      }
+      if (filterStr && !found) {
+        if (script.name && script.name.indexOf(filterStr) >= 0) {
+          found = true;
+        }
+      }
+      if (!found) continue;
+    }
+    if (types & ScriptTypeFlag(scripts[i].type)) {
+      response.body.push(MakeMirror(scripts[i]));
+    }
+  }
+};
+
+
+DebugCommandProcessor.prototype.threadsRequest_ = function(request, response) {
+  // Get the number of threads.
+  var total_threads = this.exec_state_.threadCount();
+
+  // Get information for all threads.
+  var threads = [];
+  for (var i = 0; i < total_threads; i++) {
+    var details = %GetThreadDetails(this.exec_state_.break_id, i);
+    var thread_info = { current: details[0],
+                        id: details[1]
+                      };
+    threads.push(thread_info);
+  }
+
+  // Create the response body.
+  response.body = {
+    totalThreads: total_threads,
+    threads: threads
+  };
+};
+
+
+DebugCommandProcessor.prototype.suspendRequest_ = function(request, response) {
+  response.running = false;
+};
+
+
+DebugCommandProcessor.prototype.versionRequest_ = function(request, response) {
+  response.body = {
+    V8Version: %GetV8Version()
+  };
+};
+
+
+DebugCommandProcessor.prototype.changeLiveRequest_ = function(
+    request, response) {
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+  var script_id = request.arguments.script_id;
+  var preview_only = !!request.arguments.preview_only;
+
+  var scripts = %DebugGetLoadedScripts();
+
+  var the_script = null;
+  for (var i = 0; i < scripts.length; i++) {
+    if (scripts[i].id == script_id) {
+      the_script = scripts[i];
+    }
+  }
+  if (!the_script) {
+    response.failed('Script not found');
+    return;
+  }
+
+  var change_log = new GlobalArray();
+
+  if (!IS_STRING(request.arguments.new_source)) {
+    throw "new_source argument expected";
+  }
+
+  var new_source = request.arguments.new_source;
+
+  var result_description;
+  try {
+    result_description = Debug.LiveEdit.SetScriptSource(the_script,
+        new_source, preview_only, change_log);
+  } catch (e) {
+    if (e instanceof Debug.LiveEdit.Failure && "details" in e) {
+      response.failed(e.message, e.details);
+      return;
+    }
+    throw e;
+  }
+  response.body = {change_log: change_log, result: result_description};
+
+  if (!preview_only && !this.running_ && result_description.stack_modified) {
+    response.body.stepin_recommended = true;
+  }
+};
+
+
+DebugCommandProcessor.prototype.restartFrameRequest_ = function(
+    request, response) {
+  if (!request.arguments) {
+    return response.failed('Missing arguments');
+  }
+  var frame = request.arguments.frame;
+
+  // No frames to evaluate in frame.
+  if (this.exec_state_.frameCount() == 0) {
+    return response.failed('No frames');
+  }
+
+  var frame_mirror;
+  // Check whether a frame was specified.
+  if (!IS_UNDEFINED(frame)) {
+    var frame_number = TO_NUMBER(frame);
+    if (frame_number < 0 || frame_number >= this.exec_state_.frameCount()) {
+      return response.failed('Invalid frame "' + frame + '"');
+    }
+    // Restart specified frame.
+    frame_mirror = this.exec_state_.frame(frame_number);
+  } else {
+    // Restart selected frame.
+    frame_mirror = this.exec_state_.frame();
+  }
+
+  var result_description = Debug.LiveEdit.RestartFrame(frame_mirror);
+  response.body = {result: result_description};
+};
+
+
+DebugCommandProcessor.prototype.debuggerFlagsRequest_ = function(request,
+                                                                 response) {
+  // Check for legal request.
+  if (!request.arguments) {
+    response.failed('Missing arguments');
+    return;
+  }
+
+  // Pull out arguments.
+  var flags = request.arguments.flags;
+
+  response.body = { flags: [] };
+  if (!IS_UNDEFINED(flags)) {
+    for (var i = 0; i < flags.length; i++) {
+      var name = flags[i].name;
+      var debugger_flag = debugger_flags[name];
+      if (!debugger_flag) {
+        continue;
+      }
+      if ('value' in flags[i]) {
+        debugger_flag.setValue(flags[i].value);
+      }
+      response.body.flags.push({ name: name, value: debugger_flag.getValue() });
+    }
+  } else {
+    for (var name in debugger_flags) {
+      var value = debugger_flags[name].getValue();
+      response.body.flags.push({ name: name, value: value });
+    }
+  }
+};
+
+
+DebugCommandProcessor.prototype.v8FlagsRequest_ = function(request, response) {
+  var flags = request.arguments.flags;
+  if (!flags) flags = '';
+  %SetFlags(flags);
+};
+
+
+DebugCommandProcessor.prototype.gcRequest_ = function(request, response) {
+  var type = request.arguments.type;
+  if (!type) type = 'all';
+
+  var before = %GetHeapUsage();
+  %CollectGarbage(type);
+  var after = %GetHeapUsage();
+
+  response.body = { "before": before, "after": after };
+};
+
+
+DebugCommandProcessor.prototype.dispatch_ = (function() {
+  var proto = DebugCommandProcessor.prototype;
+  return {
+    "continue":             proto.continueRequest_,
+    "break"   :             proto.breakRequest_,
+    "setbreakpoint" :       proto.setBreakPointRequest_,
+    "changebreakpoint":     proto.changeBreakPointRequest_,
+    "clearbreakpoint":      proto.clearBreakPointRequest_,
+    "clearbreakpointgroup": proto.clearBreakPointGroupRequest_,
+    "disconnect":           proto.disconnectRequest_,
+    "setexceptionbreak":    proto.setExceptionBreakRequest_,
+    "listbreakpoints":      proto.listBreakpointsRequest_,
+    "backtrace":            proto.backtraceRequest_,
+    "frame":                proto.frameRequest_,
+    "scopes":               proto.scopesRequest_,
+    "scope":                proto.scopeRequest_,
+    "setvariablevalue":     proto.setVariableValueRequest_,
+    "evaluate":             proto.evaluateRequest_,
+    "lookup":               proto.lookupRequest_,
+    "references":           proto.referencesRequest_,
+    "source":               proto.sourceRequest_,
+    "scripts":              proto.scriptsRequest_,
+    "threads":              proto.threadsRequest_,
+    "suspend":              proto.suspendRequest_,
+    "version":              proto.versionRequest_,
+    "changelive":           proto.changeLiveRequest_,
+    "restartframe":         proto.restartFrameRequest_,
+    "flags":                proto.debuggerFlagsRequest_,
+    "v8flag":               proto.v8FlagsRequest_,
+    "gc":                   proto.gcRequest_,
+  };
+})();
+
+
+// Check whether the previously processed command caused the VM to become
+// running.
+DebugCommandProcessor.prototype.isRunning = function() {
+  return this.running_;
+};
+
+
+DebugCommandProcessor.prototype.systemBreak = function(cmd, args) {
+  return %SystemBreak();
+};
+
+
+/**
+ * Convert an Object to its debugger protocol representation. The representation
+ * may be serilized to a JSON object using JSON.stringify().
+ * This implementation simply runs through all string property names, converts
+ * each property value to a protocol value and adds the property to the result
+ * object. For type "object" the function will be called recursively. Note that
+ * circular structures will cause infinite recursion.
+ * @param {Object} object The object to format as protocol object.
+ * @param {MirrorSerializer} mirror_serializer The serializer to use if any
+ *     mirror objects are encountered.
+ * @return {Object} Protocol object value.
+ */
+function ObjectToProtocolObject_(object, mirror_serializer) {
+  var content = {};
+  for (var key in object) {
+    // Only consider string keys.
+    if (typeof key == 'string') {
+      // Format the value based on its type.
+      var property_value_json = ValueToProtocolValue_(object[key],
+                                                      mirror_serializer);
+      // Add the property if relevant.
+      if (!IS_UNDEFINED(property_value_json)) {
+        content[key] = property_value_json;
+      }
+    }
+  }
+
+  return content;
+}
+
+
+/**
+ * Convert an array to its debugger protocol representation. It will convert
+ * each array element to a protocol value.
+ * @param {Array} array The array to format as protocol array.
+ * @param {MirrorSerializer} mirror_serializer The serializer to use if any
+ *     mirror objects are encountered.
+ * @return {Array} Protocol array value.
+ */
+function ArrayToProtocolArray_(array, mirror_serializer) {
+  var json = [];
+  for (var i = 0; i < array.length; i++) {
+    json.push(ValueToProtocolValue_(array[i], mirror_serializer));
+  }
+  return json;
+}
+
+
+/**
+ * Convert a value to its debugger protocol representation.
+ * @param {*} value The value to format as protocol value.
+ * @param {MirrorSerializer} mirror_serializer The serializer to use if any
+ *     mirror objects are encountered.
+ * @return {*} Protocol value.
+ */
+function ValueToProtocolValue_(value, mirror_serializer) {
+  // Format the value based on its type.
+  var json;
+  switch (typeof value) {
+    case 'object':
+      if (value instanceof Mirror) {
+        json = mirror_serializer.serializeValue(value);
+      } else if (IS_ARRAY(value)){
+        json = ArrayToProtocolArray_(value, mirror_serializer);
+      } else {
+        json = ObjectToProtocolObject_(value, mirror_serializer);
+      }
+      break;
+
+    case 'boolean':
+    case 'string':
+    case 'number':
+      json = value;
+      break;
+
+    default:
+      json = null;
+  }
+  return json;
+}
+
+
+// -------------------------------------------------------------------
+// Exports
+
+utils.InstallConstants(global, [
+  "Debug", Debug,
+  "DebugCommandProcessor", DebugCommandProcessor,
+  "BreakEvent", BreakEvent,
+  "CompileEvent", CompileEvent,
+  "BreakPoint", BreakPoint,
+]);
+
+// Functions needed by the debugger runtime.
+utils.InstallFunctions(utils, DONT_ENUM, [
+  "MakeExecutionState", MakeExecutionState,
+  "MakeExceptionEvent", MakeExceptionEvent,
+  "MakeBreakEvent", MakeBreakEvent,
+  "MakeCompileEvent", MakeCompileEvent,
+  "MakePromiseEvent", MakePromiseEvent,
+  "MakeAsyncTaskEvent", MakeAsyncTaskEvent,
+  "IsBreakPointTriggered", IsBreakPointTriggered,
+  "UpdateScriptBreakPoints", UpdateScriptBreakPoints,
+]);
+
+// Export to liveedit.js
+utils.Export(function(to) {
+  to.GetScriptBreakPoints = GetScriptBreakPoints;
+});
+
+})