Adding allocator annotations to blink classes and structs.

Source/core/fetch/CachedMetadataHandler.h

Index: Source/core/fetch/CachedMetadataHandler.h
diff --git a/Source/core/fetch/CachedMetadataHandler.h b/Source/core/fetch/CachedMetadataHandler.h
index 0f0315eb0fa618b255b6e30eb703add1020252a4..e1d65930dd853c4b3f53303ae3001c41205b39db 100644
--- a/Source/core/fetch/CachedMetadataHandler.h
+++ b/Source/core/fetch/CachedMetadataHandler.h
@@ -14,6 +14,7 @@ class CachedMetadata;
 
 // Handler class for caching operations.
 class CachedMetadataHandler : public NoBaseWillBeGarbageCollectedFinalized<CachedMetadataHandler> {
+    WTF_MAKE_FAST_ALLOCATED_WILL_BE_REMOVED(CachedMetadataHandler);
 public:
     enum CacheType {
         SendToPlatform, // send cache data to blink::Platform::cacheMetadata