Make platform/heap to use USING_FAST_MALLOC.

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

 /*
  * Copyright (C) 2014 Google Inc. 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
@@ skipping 33 matching lines @@
 
     void requestInterrupt() override
     {
         // GCTask has an empty run() method. Its only purpose is to guarantee
         // that MessageLoop will have a task to process which will result
         // in GCTaskRunner::didProcessTask being executed.
         m_taskRunner->postTask(BLINK_FROM_HERE, new GCTask);
     }
 
 private:
-    class GCTask : public WebTaskRunner::Task {
+    class GCTask final : public WebTaskRunner::Task {
+        USING_FAST_MALLOC(GCTask);
     public:
         virtual ~GCTask() { }
 
         void run() override
         {
             // Don't do anything here because we don't know if this is
             // a nested event loop or not. GCTaskRunner::didProcessTask
             // will enter correct safepoint for us.
             // We are not calling onInterrupted() because that always
             // conservatively enters safepoint with pointers on stack.
         }
     };
 
     WebTaskRunner* m_taskRunner;
 };
 
 class GCTaskObserver final : public WebThread::TaskObserver {
+    USING_FAST_MALLOC(GCTaskObserver);
 public:
     GCTaskObserver() : m_nesting(0) { }
 
     ~GCTaskObserver()
     {
         // m_nesting can be 1 if this was unregistered in a task and
         // didProcessTask was not called.
         ASSERT(!m_nesting || m_nesting == 1);
     }
 
@@ skipping 11 matching lines @@
             m_nesting--;
 
         ThreadState::current()->safePoint(m_nesting ? BlinkGC::HeapPointersOnStack : BlinkGC::NoHeapPointersOnStack);
     }
 
 private:
     int m_nesting;
 };
 
 class GCTaskRunner final {
+    USING_FAST_MALLOC(GCTaskRunner);
 public:
     explicit GCTaskRunner(WebThread* thread)
         : m_gcTaskObserver(adoptPtr(new GCTaskObserver))
         , m_thread(thread)
     {
         m_thread->addTaskObserver(m_gcTaskObserver.get());
         ThreadState::current()->addInterruptor(adoptPtr(new MessageLoopInterruptor(thread->taskRunner())));
     }
 
     ~GCTaskRunner()
     {
         m_thread->removeTaskObserver(m_gcTaskObserver.get());
     }
 
 private:
     OwnPtr<GCTaskObserver> m_gcTaskObserver;
     WebThread* m_thread;
 };
 
 } // namespace blink
 
 #endif