Make platform/heap to use USING_FAST_MALLOC.

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

Index: third_party/WebKit/Source/platform/heap/BlinkGCInterruptor.h
diff --git a/third_party/WebKit/Source/platform/heap/BlinkGCInterruptor.h b/third_party/WebKit/Source/platform/heap/BlinkGCInterruptor.h
index 8e9454ea220c1bef6da2700efac530957ca9b173..cdf14c6d0902c06ddc956ee663da196351114dfc 100644
--- a/third_party/WebKit/Source/platform/heap/BlinkGCInterruptor.h
+++ b/third_party/WebKit/Source/platform/heap/BlinkGCInterruptor.h
@@ -6,6 +6,7 @@
 #define BlinkGCInterruptor_h
 
 #include "platform/PlatformExport.h"
+#include "wtf/Allocator.h"
 
 namespace blink {
 
@@ -17,6 +18,7 @@ namespace blink {
 // to temporarily interrupt and pause this long running loop at
 // an arbitrary moment creating a safepoint for a GC.
 class PLATFORM_EXPORT BlinkGCInterruptor {
+    USING_FAST_MALLOC(BlinkGCInterruptor);
 public:
     virtual ~BlinkGCInterruptor() { }