Revert 207992: This looks like a reland of r207983, which was reverted in

trunk/src/content/renderer/renderer_webkitplatformsupport_impl.h

 // Copyright (c) 2012 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 CONTENT_RENDERER_RENDERER_WEBKITPLATFORMSUPPORT_IMPL_H_
 #define CONTENT_RENDERER_RENDERER_WEBKITPLATFORMSUPPORT_IMPL_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/platform_file.h"
@@ skipping 89 matching lines @@
       size_t buffer_size, unsigned input_channels, unsigned channels,
       double sample_rate, WebKit::WebAudioDevice::RenderCallback* callback,
       const WebKit::WebString& input_device_id);
 
   virtual bool loadAudioResource(
       WebKit::WebAudioBus* destination_bus, const char* audio_file_data,
       size_t data_size, double sample_rate);
 
   virtual WebKit::WebContentDecryptionModule* createContentDecryptionModule(
       const WebKit::WebString& key_system);
-  virtual WebKit::WebMIDIAccessor*
-      createMIDIAccessor(WebKit::WebMIDIAccessorClient* client);
 
   virtual WebKit::WebBlobRegistry* blobRegistry();
   virtual void sampleGamepads(WebKit::WebGamepads&);
   virtual WebKit::WebString userAgent(const WebKit::WebURL& url);
   virtual void GetPlugins(bool refresh,
                           std::vector<webkit::WebPluginInfo>* plugins) OVERRIDE;
   virtual WebKit::WebRTCPeerConnectionHandler* createRTCPeerConnectionHandler(
       WebKit::WebRTCPeerConnectionHandlerClient* client);
   virtual WebKit::WebMediaStreamCenter* createMediaStreamCenter(
       WebKit::WebMediaStreamCenterClient* client);
@@ skipping 61 matching lines @@
   scoped_refptr<ThreadSafeSender> thread_safe_sender_;
 
   scoped_refptr<cc::ContextProvider> shared_offscreen_context_;
 
   webkit::WebCompositorSupportImpl compositor_support_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_RENDERER_WEBKITPLATFORMSUPPORT_IMPL_H_