Make FileReader's throttle controller a supplement.

Source/core/fileapi/FileReader.h

 /*
  * Copyright (C) 2010 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 21 matching lines @@
 #define FileReader_h
 
 #include "core/dom/ActiveDOMObject.h"
 #include "core/events/EventTarget.h"
 #include "core/fileapi/FileError.h"
 #include "core/fileapi/FileReaderLoader.h"
 #include "core/fileapi/FileReaderLoaderClient.h"
 #include "platform/heap/Handle.h"
 #include "wtf/Forward.h"
 #include "wtf/RefCounted.h"
-#include "wtf/ThreadSpecific.h"
 #include "wtf/text/WTFString.h"
 
 namespace WebCore {
 
 class Blob;
 class ExceptionState;
 class ExecutionContext;
 
 class FileReader FINAL : public RefCountedWillBeGarbageCollectedFinalized<FileReader>, public ActiveDOMObject, public FileReaderLoaderClient, public EventTargetWithInlineData {
     DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCounted<FileReader>);
@@ skipping 50 matching lines @@
 private:
     class ThrottlingController;
 
     FileReader(ExecutionContext*);
 
     void terminate();
     void readInternal(Blob*, FileReaderLoader::ReadType, ExceptionState&);
     void fireErrorEvent(int httpStatusCode);
     void fireEvent(const AtomicString& type);
 
-    static ThreadSpecific<ThrottlingController>& throttlingController();
+    ThrottlingController* throttlingController();
     void executePendingRead();
 
     ReadyState m_state;
 
     // Internal loading state, which could differ from ReadyState as it's
     // for script-visible state while this one's for internal state.
     enum LoadingState {
         LoadingStateNone,
         LoadingStatePending,
         LoadingStateLoading,
         LoadingStateAborted
     };
     LoadingState m_loadingState;
 
     String m_blobType;
     RefPtr<BlobDataHandle> m_blobDataHandle;
     FileReaderLoader::ReadType m_readType;
     String m_encoding;
 
     OwnPtr<FileReaderLoader> m_loader;
     RefPtrWillBeMember<FileError> m_error;
     double m_lastProgressNotificationTimeMS;
 };
 
 } // namespace WebCore
 
 #endif // FileReader_h