diff --git a/PRESUBMIT.py b/PRESUBMIT.py
new file mode 100644
index 0000000..3a9895d
--- /dev/null
+++ b/PRESUBMIT.py
@@ -0,0 +1,256 @@
+# Copyright 2012 the V8 project authors. All rights reserved.
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+#       copyright notice, this list of conditions and the following
+#       disclaimer in the documentation and/or other materials provided
+#       with the distribution.
+#     * Neither the name of Google Inc. nor the names of its
+#       contributors may be used to endorse or promote products derived
+#       from this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+"""Top-level presubmit script for V8.
+
+See http://dev.chromium.org/developers/how-tos/depottools/presubmit-scripts
+for more details about the presubmit API built into gcl.
+"""
+
+import sys
+
+
+_EXCLUDED_PATHS = (
+    r"^test[\\\/].*",
+    r"^testing[\\\/].*",
+    r"^third_party[\\\/].*",
+    r"^tools[\\\/].*",
+)
+
+
+# Regular expression that matches code only used for test binaries
+# (best effort).
+_TEST_CODE_EXCLUDED_PATHS = (
+    r'.+-unittest\.cc',
+    # Has a method VisitForTest().
+    r'src[\\\/]compiler[\\\/]ast-graph-builder\.cc',
+    # Test extension.
+    r'src[\\\/]extensions[\\\/]gc-extension\.cc',
+)
+
+
+_TEST_ONLY_WARNING = (
+    'You might be calling functions intended only for testing from\n'
+    'production code.  It is OK to ignore this warning if you know what\n'
+    'you are doing, as the heuristics used to detect the situation are\n'
+    'not perfect.  The commit queue will not block on this warning.')
+
+
+def _V8PresubmitChecks(input_api, output_api):
+  """Runs the V8 presubmit checks."""
+  import sys
+  sys.path.append(input_api.os_path.join(
+        input_api.PresubmitLocalPath(), 'tools'))
+  from presubmit import CppLintProcessor
+  from presubmit import SourceProcessor
+  from presubmit import CheckRuntimeVsNativesNameClashes
+  from presubmit import CheckExternalReferenceRegistration
+
+  results = []
+  if not CppLintProcessor().Run(input_api.PresubmitLocalPath()):
+    results.append(output_api.PresubmitError("C++ lint check failed"))
+  if not SourceProcessor().Run(input_api.PresubmitLocalPath()):
+    results.append(output_api.PresubmitError(
+        "Copyright header, trailing whitespaces and two empty lines " \
+        "between declarations check failed"))
+  if not CheckRuntimeVsNativesNameClashes(input_api.PresubmitLocalPath()):
+    results.append(output_api.PresubmitError(
+        "Runtime/natives name clash check failed"))
+  if not CheckExternalReferenceRegistration(input_api.PresubmitLocalPath()):
+    results.append(output_api.PresubmitError(
+        "External references registration check failed"))
+  return results
+
+
+def _CheckUnwantedDependencies(input_api, output_api):
+  """Runs checkdeps on #include statements added in this
+  change. Breaking - rules is an error, breaking ! rules is a
+  warning.
+  """
+  # We need to wait until we have an input_api object and use this
+  # roundabout construct to import checkdeps because this file is
+  # eval-ed and thus doesn't have __file__.
+  original_sys_path = sys.path
+  try:
+    sys.path = sys.path + [input_api.os_path.join(
+        input_api.PresubmitLocalPath(), 'buildtools', 'checkdeps')]
+    import checkdeps
+    from cpp_checker import CppChecker
+    from rules import Rule
+  finally:
+    # Restore sys.path to what it was before.
+    sys.path = original_sys_path
+
+  added_includes = []
+  for f in input_api.AffectedFiles():
+    if not CppChecker.IsCppFile(f.LocalPath()):
+      continue
+
+    changed_lines = [line for line_num, line in f.ChangedContents()]
+    added_includes.append([f.LocalPath(), changed_lines])
+
+  deps_checker = checkdeps.DepsChecker(input_api.PresubmitLocalPath())
+
+  error_descriptions = []
+  warning_descriptions = []
+  for path, rule_type, rule_description in deps_checker.CheckAddedCppIncludes(
+      added_includes):
+    description_with_path = '%s\n    %s' % (path, rule_description)
+    if rule_type == Rule.DISALLOW:
+      error_descriptions.append(description_with_path)
+    else:
+      warning_descriptions.append(description_with_path)
+
+  results = []
+  if error_descriptions:
+    results.append(output_api.PresubmitError(
+        'You added one or more #includes that violate checkdeps rules.',
+        error_descriptions))
+  if warning_descriptions:
+    results.append(output_api.PresubmitPromptOrNotify(
+        'You added one or more #includes of files that are temporarily\n'
+        'allowed but being removed. Can you avoid introducing the\n'
+        '#include? See relevant DEPS file(s) for details and contacts.',
+        warning_descriptions))
+  return results
+
+
+def _CheckNoProductionCodeUsingTestOnlyFunctions(input_api, output_api):
+  """Attempts to prevent use of functions intended only for testing in
+  non-testing code. For now this is just a best-effort implementation
+  that ignores header files and may have some false positives. A
+  better implementation would probably need a proper C++ parser.
+  """
+  # We only scan .cc files, as the declaration of for-testing functions in
+  # header files are hard to distinguish from calls to such functions without a
+  # proper C++ parser.
+  file_inclusion_pattern = r'.+\.cc'
+
+  base_function_pattern = r'[ :]test::[^\s]+|ForTest(ing)?|for_test(ing)?'
+  inclusion_pattern = input_api.re.compile(r'(%s)\s*\(' % base_function_pattern)
+  comment_pattern = input_api.re.compile(r'//.*(%s)' % base_function_pattern)
+  exclusion_pattern = input_api.re.compile(
+    r'::[A-Za-z0-9_]+(%s)|(%s)[^;]+\{' % (
+      base_function_pattern, base_function_pattern))
+
+  def FilterFile(affected_file):
+    black_list = (_EXCLUDED_PATHS +
+                  _TEST_CODE_EXCLUDED_PATHS +
+                  input_api.DEFAULT_BLACK_LIST)
+    return input_api.FilterSourceFile(
+      affected_file,
+      white_list=(file_inclusion_pattern, ),
+      black_list=black_list)
+
+  problems = []
+  for f in input_api.AffectedSourceFiles(FilterFile):
+    local_path = f.LocalPath()
+    for line_number, line in f.ChangedContents():
+      if (inclusion_pattern.search(line) and
+          not comment_pattern.search(line) and
+          not exclusion_pattern.search(line)):
+        problems.append(
+          '%s:%d\n    %s' % (local_path, line_number, line.strip()))
+
+  if problems:
+    return [output_api.PresubmitPromptOrNotify(_TEST_ONLY_WARNING, problems)]
+  else:
+    return []
+
+
+def _CommonChecks(input_api, output_api):
+  """Checks common to both upload and commit."""
+  results = []
+  results.extend(input_api.canned_checks.CheckOwners(
+      input_api, output_api, source_file_filter=None))
+  results.extend(input_api.canned_checks.CheckPatchFormatted(
+      input_api, output_api))
+  results.extend(_V8PresubmitChecks(input_api, output_api))
+  results.extend(_CheckUnwantedDependencies(input_api, output_api))
+  results.extend(
+      _CheckNoProductionCodeUsingTestOnlyFunctions(input_api, output_api))
+  return results
+
+
+def _SkipTreeCheck(input_api, output_api):
+  """Check the env var whether we want to skip tree check.
+     Only skip if src/version.cc has been updated."""
+  src_version = 'src/version.cc'
+  FilterFile = lambda file: file.LocalPath() == src_version
+  if not input_api.AffectedSourceFiles(
+      lambda file: file.LocalPath() == src_version):
+    return False
+  return input_api.environ.get('PRESUBMIT_TREE_CHECK') == 'skip'
+
+
+def _CheckChangeLogFlag(input_api, output_api):
+  """Checks usage of LOG= flag in the commit message."""
+  results = []
+  if input_api.change.BUG and not 'LOG' in input_api.change.tags:
+    results.append(output_api.PresubmitError(
+        'An issue reference (BUG=) requires a change log flag (LOG=). '
+        'Use LOG=Y for including this commit message in the change log. '
+        'Use LOG=N or leave blank otherwise.'))
+  return results
+
+
+def CheckChangeOnUpload(input_api, output_api):
+  results = []
+  results.extend(_CommonChecks(input_api, output_api))
+  results.extend(_CheckChangeLogFlag(input_api, output_api))
+  return results
+
+
+def CheckChangeOnCommit(input_api, output_api):
+  results = []
+  results.extend(_CommonChecks(input_api, output_api))
+  results.extend(_CheckChangeLogFlag(input_api, output_api))
+  results.extend(input_api.canned_checks.CheckChangeHasDescription(
+      input_api, output_api))
+  if not _SkipTreeCheck(input_api, output_api):
+    results.extend(input_api.canned_checks.CheckTreeIsOpen(
+        input_api, output_api,
+        json_url='http://v8-status.appspot.com/current?format=json'))
+  return results
+
+
+def GetPreferredTryMasters(project, change):
+  return {
+    'tryserver.v8': {
+      'v8_linux_rel': set(['defaulttests']),
+      'v8_linux_dbg': set(['defaulttests']),
+      'v8_linux_nosnap_rel': set(['defaulttests']),
+      'v8_linux_nosnap_dbg': set(['defaulttests']),
+      'v8_linux64_rel': set(['defaulttests']),
+      'v8_linux_arm_dbg': set(['defaulttests']),
+      'v8_linux_arm64_rel': set(['defaulttests']),
+      'v8_linux_layout_dbg': set(['defaulttests']),
+      'v8_mac_rel': set(['defaulttests']),
+      'v8_win_rel': set(['defaulttests']),
+      'v8_win64_compile_rel': set(['defaulttests']),
+    },
+  }