Make platform/heap to use USING_FAST_MALLOC.

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

Index: third_party/WebKit/Source/platform/heap/SafePoint.h
diff --git a/third_party/WebKit/Source/platform/heap/SafePoint.h b/third_party/WebKit/Source/platform/heap/SafePoint.h
index 0b96633b51b4b40dcd08a8fa33228eb410f5901a..4e3c8f45377b52bc8e28b183486132f72ba49553 100644
--- a/third_party/WebKit/Source/platform/heap/SafePoint.h
+++ b/third_party/WebKit/Source/platform/heap/SafePoint.h
@@ -11,6 +11,7 @@
 namespace blink {
 
 class SafePointScope final {
+    STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(SafePointScope);
 public:
     explicit SafePointScope(BlinkGC::StackState stackState, ThreadState* state = ThreadState::current())
@@ -38,6 +39,7 @@ private:
 // leaveSafePoint method cannot complete without blocking, see
 // SafePointBarrier::checkAndPark.
 class SafePointAwareMutexLocker final {
+    STACK_ALLOCATED();
     WTF_MAKE_NONCOPYABLE(SafePointAwareMutexLocker);
 public:
     explicit SafePointAwareMutexLocker(MutexBase& mutex, BlinkGC::StackState stackState = BlinkGC::HeapPointersOnStack)
@@ -88,6 +90,7 @@ private:
 };
 
 class SafePointBarrier final {
+    USING_FAST_MALLOC(SafePointBarrier);
     WTF_MAKE_NONCOPYABLE(SafePointBarrier);
 public:
     SafePointBarrier();