Update V8 to r5091 as required by WebKit r63859.

Change-Id: I8e35d765e6f6c7f89eccff900e1cabe2d5dd6110
diff --git a/src/mark-compact.cc b/src/mark-compact.cc
index 95afb4a..d9b0222 100644
--- a/src/mark-compact.cc
+++ b/src/mark-compact.cc
@@ -28,6 +28,7 @@
 #include "v8.h"
 
 #include "execution.h"
+#include "heap-profiler.h"
 #include "global-handles.h"
 #include "ic-inl.h"
 #include "mark-compact.h"
@@ -425,8 +426,10 @@
   // Since the descriptor array has been marked already, it is fine
   // that one of these fields contains a pointer to it.
   MarkingVisitor visitor;  // Has no state or contents.
-  visitor.VisitPointers(HeapObject::RawField(map, Map::kPrototypeOffset),
-                        HeapObject::RawField(map, Map::kSize));
+  visitor.VisitPointers(HeapObject::RawField(map,
+                                             Map::kPointerFieldsBeginOffset),
+                        HeapObject::RawField(map,
+                                             Map::kPointerFieldsEndOffset));
 }
 
 
@@ -2216,6 +2219,7 @@
   if (copied_to->IsJSFunction()) {
     PROFILE(FunctionMoveEvent(old_addr, new_addr));
   }
+  HEAP_PROFILE(ObjectMoveEvent(old_addr, new_addr));
 
   return obj_size;
 }
@@ -2262,6 +2266,7 @@
     // Notify the logger that compiled code has moved.
     PROFILE(CodeMoveEvent(old_addr, new_addr));
   }
+  HEAP_PROFILE(ObjectMoveEvent(old_addr, new_addr));
 
   return obj_size;
 }
@@ -2306,6 +2311,7 @@
   if (copied_to->IsJSFunction()) {
     PROFILE(FunctionMoveEvent(old_addr, new_addr));
   }
+  HEAP_PROFILE(ObjectMoveEvent(old_addr, new_addr));
 
   return obj_size;
 }