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

trunk/src/content/renderer/media/midi_message_filter.h

Index: trunk/src/content/renderer/media/midi_message_filter.h
===================================================================
--- trunk/src/content/renderer/media/midi_message_filter.h	(revision 207994)
+++ trunk/src/content/renderer/media/midi_message_filter.h	(working copy)
@@ -1,116 +0,0 @@
-// Copyright (c) 2013 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_MEDIA_MIDI_MESSAGE_FILTER_H_
-#define CONTENT_RENDERER_MEDIA_MIDI_MESSAGE_FILTER_H_
-
-#include <map>
-#include <vector>
-
-#include "base/memory/scoped_ptr.h"
-#include "content/common/content_export.h"
-#include "ipc/ipc_channel_proxy.h"
-#include "media/midi/midi_port_info.h"
-#include "third_party/WebKit/public/platform/WebMIDIAccessor.h"
-#include "third_party/WebKit/public/platform/WebMIDIAccessorClient.h"
-
-namespace base {
-class MessageLoopProxy;
-}
-
-namespace content {
-
-// MessageFilter that handles MIDI messages.
-class CONTENT_EXPORT MIDIMessageFilter
-    : public IPC::ChannelProxy::MessageFilter {
- public:
-  explicit MIDIMessageFilter(
-      const scoped_refptr<base::MessageLoopProxy>& io_message_loop);
-
-  // Each client registers for MIDI access here.
-  // If permission is granted, then the client's
-  // addInputPort() and addOutputPort() methods will be called,
-  // giving the client access to receive and send data.
-  void RequestAccess(WebKit::WebMIDIAccessorClient* client, int access);
-  void RemoveClient(WebKit::WebMIDIAccessorClient* client);
-
-  // A client will only be able to call this method if it has a suitable
-  // output port (from addOutputPort()).
-  void SendMIDIData(int port,
-                    const uint8* data,
-                    size_t length,
-                    double timestamp);
-
-  // IO message loop associated with this message filter.
-  scoped_refptr<base::MessageLoopProxy> io_message_loop() const {
-    return io_message_loop_;
-  }
-
- protected:
-  virtual ~MIDIMessageFilter();
-
- private:
-  // Sends an IPC message using |channel_|.
-  void Send(IPC::Message* message);
-
-  // IPC::ChannelProxy::MessageFilter override. Called on |io_message_loop|.
-  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
-  virtual void OnFilterAdded(IPC::Channel* channel) OVERRIDE;
-  virtual void OnFilterRemoved() OVERRIDE;
-  virtual void OnChannelClosing() OVERRIDE;
-
-  // Called when the browser process has approved (or denied) access to
-  // MIDI hardware.
-  void OnAccessApproved(int client_id,
-                        int access,
-                        bool success,
-                        media::MIDIPortInfoList inputs,
-                        media::MIDIPortInfoList outputs);
-
-  // Called when the browser process has sent MIDI data containing one or
-  // more messages.
-  void OnDataReceived(int port,
-                      const std::vector<uint8>& data,
-                      double timestamp);
-
-  void HandleAccessApproved(int client_id,
-                            int access,
-                            bool success,
-                            media::MIDIPortInfoList inputs,
-                            media::MIDIPortInfoList outputs);
-
-  void HandleDataReceived(int port,
-                          const std::vector<uint8>& data,
-                          double timestamp);
-
-  void RequestAccessOnIOThread(int client_id, int access);
-
-  void SendMIDIDataOnIOThread(int port,
-                              const std::vector<uint8>& data,
-                              double timestamp);
-
-  WebKit::WebMIDIAccessorClient* GetClientFromId(int client_id);
-
-  // IPC channel for Send(); must only be accessed on |io_message_loop_|.
-  IPC::Channel* channel_;
-
-  // Message loop on which IPC calls are driven.
-  const scoped_refptr<base::MessageLoopProxy> io_message_loop_;
-
-  // Keeps track of all MIDI clients.
-  // We map client to "client id" used to track permission.
-  // When access has been approved, we add the input and output ports to
-  // the client, allowing it to actually receive and send MIDI data.
-  typedef std::map<WebKit::WebMIDIAccessorClient*, int> ClientsMap;
-  ClientsMap clients_;
-
-  // Dishes out client ids.
-  int next_available_id_;
-
-  DISALLOW_COPY_AND_ASSIGN(MIDIMessageFilter);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_MIDI_MESSAGE_FILTER_H_