Disable collection backing reallocation during pre finalizer

third_party/WebKit/Source/platform/heap/ThreadState.h

Index: third_party/WebKit/Source/platform/heap/ThreadState.h
diff --git a/third_party/WebKit/Source/platform/heap/ThreadState.h b/third_party/WebKit/Source/platform/heap/ThreadState.h
index 34b1ad25ece4b84fe5197863e3415a89616ff738..9e4ff8bd5666c13e7ee29d5d72e64132b6243ad1 100644
--- a/third_party/WebKit/Source/platform/heap/ThreadState.h
+++ b/third_party/WebKit/Source/platform/heap/ThreadState.h
@@ -158,6 +158,22 @@ class PLATFORM_EXPORT ThreadState {
     ThreadState* state_;
   };
 
+  class ObjectRessurectionForbiddenScope final {

[haraken, 2017/04/12 11:03:37]

Add a class-level comment.

[keishi, 2017/04/13 05:22:43]

Done.

+    STACK_ALLOCATED();
+
+   public:
+    explicit ObjectRessurectionForbiddenScope(ThreadState* state)
+        : state_(state) {
+      state_->EnterObjectRessurectionForbiddenScope();
+    }
+    ~ObjectRessurectionForbiddenScope() {
+      state_->LeaveObjectRessurectionForbiddenScope();
+    }
+
+   private:
+    ThreadState* state_;
+  };
+
   static void AttachMainThread();
 
   // Associate ThreadState object with the current thread. After this
@@ -261,6 +277,17 @@ class PLATFORM_EXPORT ThreadState {
     mixins_being_constructed_count_--;
   }
   bool SweepForbidden() const { return sweep_forbidden_; }
+  bool IsObjectRessurectionForbidden() const {
+    return object_ressurection_forbidden_;
+  }
+  void EnterObjectRessurectionForbiddenScope() {
+    DCHECK(!object_ressurection_forbidden_);
+    object_ressurection_forbidden_ = true;
+  }
+  void LeaveObjectRessurectionForbiddenScope() {
+    DCHECK(object_ressurection_forbidden_);
+    object_ressurection_forbidden_ = false;
+  }
 
   class MainThreadGCForbiddenScope final {
     STACK_ALLOCATED();
@@ -625,6 +652,7 @@ class PLATFORM_EXPORT ThreadState {
   size_t gc_forbidden_count_;
   size_t mixins_being_constructed_count_;
   double accumulated_sweeping_time_;
+  bool object_ressurection_forbidden_;
 
   BaseArena* arenas_[BlinkGC::kNumberOfArenas];
   int vector_backing_arena_index_;