[heap] Prevent leakage of GCCallbacksScope outside of heap.

src/heap/heap.h

 // 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.
 
 #ifndef V8_HEAP_HEAP_H_
 #define V8_HEAP_HEAP_H_
 
 #include <cmath>
 #include <map>
 
@@ skipping 2412 matching lines @@
 class AlwaysAllocateScope {
  public:
   explicit inline AlwaysAllocateScope(Isolate* isolate);
   inline ~AlwaysAllocateScope();
 
  private:
   Heap* heap_;
 };
 
 
-class GCCallbacksScope {
- public:
-  explicit inline GCCallbacksScope(Heap* heap);
-  inline ~GCCallbacksScope();
-
-  inline bool CheckReenter();
-
- private:
-  Heap* heap_;
-};
-
-
 // Visitor class to verify interior pointers in spaces that do not contain
 // or care about intergenerational references. All heap object pointers have to
 // point into the heap to a location that has a map pointer at its first word.
 // Caveat: Heap::Contains is an approximation because it can return true for
 // objects in a heap space but above the allocation pointer.
 class VerifyPointersVisitor : public ObjectVisitor {
  public:
   inline void VisitPointers(Object** start, Object** end);
 };
 
@@ skipping 289 matching lines @@
   DisallowHeapAllocation no_allocation;  // i.e. no gc allowed.
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(PathTracer);
 };
 #endif  // DEBUG
 }
 }  // namespace v8::internal
 
 #endif  // V8_HEAP_HEAP_H_