Simple BlinkGC heap compaction.

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

 // Copyright 2015 The Chromium 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 HeapAllocator_h
 #define HeapAllocator_h
 
 #include "platform/heap/Heap.h"
 #include "platform/heap/Persistent.h"
 #include "platform/heap/TraceTraits.h"
@@ skipping 170 matching lines @@
   }
 
 #if ENABLE(ASSERT)
   template <typename VisitorDispatcher>
   static bool weakTableRegistered(VisitorDispatcher visitor,
                                   const void* closure) {
     return visitor->weakTableRegistered(closure);
   }
 #endif
 
+  template <typename T, typename VisitorDispatcher>
+  static void registerBackingStoreReference(VisitorDispatcher visitor,
+                                            T** slot) {
+    visitor->registerBackingStoreReference(slot);
+  }
+
+  template <typename T, typename VisitorDispatcher>
+  static void registerBackingStoreCallback(VisitorDispatcher visitor,
+                                           T* backingStore,
+                                           MovingObjectCallback callback,
+                                           void* callbackData) {
+    visitor->registerBackingStoreCallback(backingStore, callback, callbackData);
+  }
+
   static void enterGCForbiddenScope() {
     ThreadState::current()->enterGCForbiddenScope();
   }
 
   static void leaveGCForbiddenScope() {
     ThreadState::current()->leaveGCForbiddenScope();
   }
 
  private:
   static void backingFree(void*);
@@ skipping 570 matching lines @@
     const blink::HeapHashCountedSet<Value, HashFunctions, Traits>& set,
     VectorType& vector) {
   copyToVector(static_cast<const HashCountedSet<Value, HashFunctions, Traits,
                                                 blink::HeapAllocator>&>(set),
                vector);
 }
 
 }  // namespace WTF
 
 #endif