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

trunk/src/media/midi/midi_manager.h

Index: trunk/src/media/midi/midi_manager.h
===================================================================
--- trunk/src/media/midi/midi_manager.h	(revision 207994)
+++ trunk/src/media/midi/midi_manager.h	(working copy)
@@ -1,109 +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 MEDIA_MIDI_MIDI_MANAGER_H_
-#define MEDIA_MIDI_MIDI_MANAGER_H_
-
-#include <set>
-
-#include "base/basictypes.h"
-#include "base/synchronization/lock.h"
-#include "media/base/media_export.h"
-#include "media/midi/midi_port_info.h"
-
-namespace media {
-
-// A MIDIManagerClient registers with the MIDIManager to receive MIDI data.
-// See MIDIManager::RequestAccess() and MIDIManager::ReleaseAccess()
-// for details.
-class MEDIA_EXPORT MIDIManagerClient {
- public:
-   virtual ~MIDIManagerClient() {}
-
-  // ReceiveMIDIData() is called when MIDI data has been received from the
-  // MIDI system.
-  // |port_index| represents the specific input port from input_ports().
-  // |data| represents a series of bytes encoding one or more MIDI messages.
-  // |length| is the number of bytes in |data|.
-  // |timestamp| is the time the data was received, in seconds.
-  virtual void ReceiveMIDIData(int port_index,
-                               const uint8* data,
-                               size_t length,
-                               double timestamp) = 0;
-};
-
-// Manages access to all MIDI hardware.
-class MEDIA_EXPORT MIDIManager {
- public:
-  enum AccessType {
-    kNoSystemExclusive,
-    kSystemExclusive
-  };
-
-  static MIDIManager* Create();
-
-  MIDIManager();
-  virtual ~MIDIManager();
-
-  // A client calls RequestAccess() to receive and send MIDI data.
-  // If access is approved, the MIDI system is lazily initialized
-  // and the client is registered to receive MIDI data.
-  // Returns |true| if access is approved.
-  bool RequestAccess(MIDIManagerClient* client, int access);
-
-  // A client calls ReleaseAccess() to stop receiving MIDI data.
-  void ReleaseAccess(MIDIManagerClient* client);
-
-  // SendMIDIData() sends one or more messages at the given time.
-  // |port_index| represents the specific output port from output_ports().
-  // |data| represents a series of bytes encoding one or more MIDI messages.
-  // |length| is the number of bytes in |data|.
-  // |timestamp| is the time to send the data, in seconds.
-  virtual void SendMIDIData(int port_index,
-                            const uint8* data,
-                            size_t length,
-                            double timestamp) = 0;
-
-  // input_ports() is a list of MIDI ports for receiving MIDI data.
-  // Each individual port in this list can be identified by its
-  // integer index into this list.
-  const MIDIPortInfoList& input_ports() { return input_ports_; }
-
-  // output_ports() is a list of MIDI ports for sending MIDI data.
-  // Each individual port in this list can be identified by its
-  // integer index into this list.
-  const MIDIPortInfoList& output_ports() { return output_ports_; }
-
- protected:
-  // Initializes the MIDI system, returning |true| on success.
-  virtual bool Initialize() = 0;
-
-  void AddInputPort(const MIDIPortInfo& info);
-  void AddOutputPort(const MIDIPortInfo& info);
-
-  // Dispatches to all clients.
-  void ReceiveMIDIData(
-      int port_index,
-      const uint8* data,
-      size_t length,
-      double timestamp);
-
-  bool initialized_;
-
-  // Keeps track of all clients who wish to receive MIDI data.
-  typedef std::set<MIDIManagerClient*> ClientList;
-  ClientList clients_;
-
-  // Protects access to our clients.
-  base::Lock clients_lock_;
-
-  MIDIPortInfoList input_ports_;
-  MIDIPortInfoList output_ports_;
-
-  DISALLOW_COPY_AND_ASSIGN(MIDIManager);
-};
-
-}  // namespace media
-
-#endif  // MEDIA_MIDI_MIDI_MANAGER_H_