Make platform/heap to use USING_FAST_MALLOC.

third_party/WebKit/Source/platform/heap/Heap.cpp

Index: third_party/WebKit/Source/platform/heap/Heap.cpp
diff --git a/third_party/WebKit/Source/platform/heap/Heap.cpp b/third_party/WebKit/Source/platform/heap/Heap.cpp
index 4972af8d0f2acdb66bba58274e7319c156d4f192..9932fd43d047366a28a8a8332073ec1ee757bca0 100644
--- a/third_party/WebKit/Source/platform/heap/Heap.cpp
+++ b/third_party/WebKit/Source/platform/heap/Heap.cpp
@@ -51,6 +51,7 @@
 namespace blink {
 
 class GCForbiddenScope final {
+    DISALLOW_NEW();
 public:
     explicit GCForbiddenScope(ThreadState* state)
         : m_state(state)
@@ -69,6 +70,7 @@ private:
 };
 
 class GCScope final {
+    STACK_ALLOCATED();
 public:
     GCScope(ThreadState* state, BlinkGC::StackState stackState, BlinkGC::GCType gcType)
         : m_state(state)
@@ -127,7 +129,8 @@ private:
     OwnPtr<Visitor> m_visitor;
 };
 
-class ResumeThreadScope {
+class ResumeThreadScope final {
+    STACK_ALLOCATED();
 public:
     explicit ResumeThreadScope(BlinkGC::GCType gcType)
         : m_resumeThreads(gcType != BlinkGC::ThreadTerminationGC)