Decouple GamepadSharedMemory into Blink.

third_party/WebKit/Source/modules/gamepad/GamepadDispatcher.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef GamepadDispatcher_h
 #define GamepadDispatcher_h
 
 #include "core/frame/PlatformEventDispatcher.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebGamepad.h"
 #include "public/platform/WebGamepadListener.h"
 
 namespace blink {
 
+class GamepadSharedMemoryReader;
 class WebGamepads;
 
 class GamepadDispatcher final
     : public GarbageCollectedFinalized<GamepadDispatcher>,
       public PlatformEventDispatcher,
       public WebGamepadListener {
   USING_GARBAGE_COLLECTED_MIXIN(GamepadDispatcher);
 
  public:
   static GamepadDispatcher& instance();
@@ skipping 22 matching lines @@
 
   // PlatformEventDispatcher
   void startListening() override;
   void stopListening() override;
 
   void dispatchDidConnectOrDisconnectGamepad(unsigned index,
                                              const WebGamepad&,
                                              bool connected);
 
   ConnectionChange m_latestChange;
+  std::unique_ptr<GamepadSharedMemoryReader> m_reader;
 };
 
 }  // namespace blink
 
 #endif