Revert 207983 "Implement Web MIDI API back-end"

> Implement Web MIDI API back-end
> 
> This involves browser-side support and IPC for sending and receiving
> MIDI messages.  Initially support for OSX is included.
> 
> BUG=163795
> R=palmer@chromium.org, piman@chromium.org, scherkus@chromium.org
> 
> Review URL: https://codereview.chromium.org/16025005

TBR=crogers@google.com

Review URL: https://codereview.chromium.org/17334006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@207989 0039d316-1c4b-4281-b951-d872f2087c98

19 files changed, 1 insertions, 647 deletions

diff --git a/content/browser/DEPS b/content/browser/DEPS
index 67ca2ef..c447bea 100644
--- a/content/browser/DEPS
+++ b/content/browser/DEPS
@@ -5,7 +5,6 @@ include_rules = [
   "+content/child/webkitplatformsupport_impl.h",  # For in-process webkit
   "+media/audio",  # For audio input for speech input feature.
   "+media/base",  # For Android JNI registration.
-  "+media/midi",  # For Web MIDI API
   "+sql",
   "+ui/webui",
   "+win8/util",
diff --git a/content/browser/browser_main_loop.cc b/content/browser/browser_main_loop.cc
index 9599d85..4e1411d 100644
--- a/content/browser/browser_main_loop.cc
+++ b/content/browser/browser_main_loop.cc
@@ -47,7 +47,6 @@
 #include "crypto/nss_util.h"
 #include "media/audio/audio_manager.h"
 #include "media/base/media.h"
-#include "media/midi/midi_manager.h"
 #include "net/base/network_change_notifier.h"
 #include "net/socket/client_socket_factory.h"
 #include "net/ssl/ssl_config_service.h"
@@ -401,10 +400,7 @@ void BrowserMainLoop::MainMessageLoopStart() {
     TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:AudioMan")
     audio_manager_.reset(media::AudioManager::Create());
   }
-  {
-    TRACE_EVENT0("startup", "BrowserMainLoop::Subsystem:MIDIManager")
-    midi_manager_.reset(media::MIDIManager::Create());
-  }
+
 
 #if !defined(OS_IOS)
   {
diff --git a/content/browser/browser_main_loop.h b/content/browser/browser_main_loop.h
index fc412cc..0317e03 100644
--- a/content/browser/browser_main_loop.h
+++ b/content/browser/browser_main_loop.h
@@ -20,7 +20,6 @@ class SystemMonitor;
 
 namespace media {
 class AudioManager;
-class MIDIManager;
 }
 
 namespace net {
@@ -82,7 +81,6 @@ class BrowserMainLoop {
   MediaStreamManager* media_stream_manager() const {
     return media_stream_manager_.get();
   }
-  media::MIDIManager* midi_manager() const { return midi_manager_.get(); }
 
  private:
   class MemoryObserver;
@@ -108,7 +106,6 @@ class BrowserMainLoop {
   scoped_ptr<HighResolutionTimerManager> hi_res_timer_manager_;
   scoped_ptr<net::NetworkChangeNotifier> network_change_notifier_;
   scoped_ptr<media::AudioManager> audio_manager_;
-  scoped_ptr<media::MIDIManager> midi_manager_;
   scoped_ptr<AudioMirroringManager> audio_mirroring_manager_;
   scoped_ptr<MediaStreamManager> media_stream_manager_;
   // Per-process listener for online state changes.
diff --git a/content/browser/renderer_host/media/midi_host.cc b/content/browser/renderer_host/media/midi_host.cc
deleted file mode 100644
index 56f4099..0000000
--- a/content/browser/renderer_host/media/midi_host.cc
+++ /dev/null
@@ -1,99 +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.
-
-#include "content/browser/renderer_host/media/midi_host.h"
-
-#include "base/bind.h"
-#include "base/bind_helpers.h"
-#include "base/debug/trace_event.h"
-#include "base/process.h"
-#include "content/browser/browser_main_loop.h"
-#include "content/browser/media/media_internals.h"
-#include "content/common/media/midi_messages.h"
-#include "content/public/browser/content_browser_client.h"
-#include "content/public/browser/media_observer.h"
-#include "media/midi/midi_manager.h"
-
-using media::MIDIManager;
-using media::MIDIPortInfoList;
-
-namespace content {
-
-MIDIHost::MIDIHost(media::MIDIManager* midi_manager)
-    : midi_manager_(midi_manager) {
-}
-
-MIDIHost::~MIDIHost() {
-  if (midi_manager_)
-    midi_manager_->ReleaseAccess(this);
-}
-
-void MIDIHost::OnChannelClosing() {
-  DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-
-  BrowserMessageFilter::OnChannelClosing();
-}
-
-void MIDIHost::OnDestruct() const {
-  BrowserThread::DeleteOnIOThread::Destruct(this);
-}
-
-///////////////////////////////////////////////////////////////////////////////
-// IPC Messages handler
-bool MIDIHost::OnMessageReceived(const IPC::Message& message,
-                                 bool* message_was_ok) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP_EX(MIDIHost, message, *message_was_ok)
-    IPC_MESSAGE_HANDLER(MIDIHostMsg_RequestAccess, OnRequestAccess)
-    IPC_MESSAGE_HANDLER(MIDIHostMsg_SendData, OnSendData)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP_EX()
-
-  return handled;
-}
-
-void MIDIHost::OnRequestAccess(int client_id, int access) {
-  MIDIPortInfoList input_ports;
-  MIDIPortInfoList output_ports;
-
-  // Ask permission and register to receive MIDI data.
-  bool approved = false;
-  if (midi_manager_) {
-    approved = midi_manager_->RequestAccess(this, access);
-    if (approved) {
-      input_ports = midi_manager_->input_ports();
-      output_ports = midi_manager_->output_ports();
-    }
-  }
-
-  Send(new MIDIMsg_AccessApproved(
-       client_id,
-       access,
-       approved,
-       input_ports,
-       output_ports));
-}
-
-void MIDIHost::OnSendData(int port,
-                          const std::vector<uint8>& data,
-                          double timestamp) {
-  // TODO(crogers): we need to post this to a dedicated thread for
-  // sending MIDI. For now, we will not implement the sending of MIDI data.
-  NOTIMPLEMENTED();
-  // if (midi_manager_)
-  //   midi_manager_->SendMIDIData(port, data.data(), data.size(), timestamp);
-}
-
-void MIDIHost::ReceiveMIDIData(
-    int port_index,
-    const uint8* data,
-    size_t length,
-    double timestamp) {
-  TRACE_EVENT0("midi", "MIDIHost::ReceiveMIDIData");
-  // Send to the renderer.
-  std::vector<uint8> v(data, data + length);
-  Send(new MIDIMsg_DataReceived(port_index, v, timestamp));
-}
-
-}  // namespace content
diff --git a/content/browser/renderer_host/media/midi_host.h b/content/browser/renderer_host/media/midi_host.h
deleted file mode 100644
index e46ed53..0000000
--- a/content/browser/renderer_host/media/midi_host.h
+++ /dev/null
@@ -1,62 +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_BROWSER_RENDERER_HOST_MEDIA_MIDI_HOST_H_
-#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_MIDI_HOST_H_
-
-#include "base/memory/ref_counted.h"
-#include "base/memory/scoped_ptr.h"
-#include "content/common/content_export.h"
-#include "content/public/browser/browser_message_filter.h"
-#include "content/public/browser/browser_thread.h"
-#include "media/midi/midi_manager.h"
-
-namespace media {
-class MIDIManager;
-}
-
-namespace content {
-
-class CONTENT_EXPORT MIDIHost
-    : public BrowserMessageFilter,
-      public media::MIDIManagerClient {
- public:
-  // Called from UI thread from the owner of this object.
-  MIDIHost(media::MIDIManager* midi_manager);
-
-  // BrowserMessageFilter implementation.
-  virtual void OnChannelClosing() OVERRIDE;
-  virtual void OnDestruct() const OVERRIDE;
-  virtual bool OnMessageReceived(const IPC::Message& message,
-                                 bool* message_was_ok) OVERRIDE;
-
-  // MIDIManagerClient implementation.
-  virtual void ReceiveMIDIData(
-      int port_index,
-      const uint8* data,
-      size_t length,
-      double timestamp) OVERRIDE;
-
-  // Request access to MIDI hardware.
-  void OnRequestAccess(int client_id, int access);
-
-  // Data to be sent to a MIDI output port.
-  void OnSendData(int port,
-                  const std::vector<uint8>& data,
-                  double timestamp);
-
- private:
-  friend class base::DeleteHelper<MIDIHost>;
-  friend class BrowserThread;
-
-  virtual ~MIDIHost();
-
-  media::MIDIManager* const midi_manager_;
-
-  DISALLOW_COPY_AND_ASSIGN(MIDIHost);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_MIDI_HOST_H_
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 20b7b99..65268c1 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -73,7 +73,6 @@
 #include "content/browser/renderer_host/media/audio_mirroring_manager.h"
 #include "content/browser/renderer_host/media/audio_renderer_host.h"
 #include "content/browser/renderer_host/media/media_stream_dispatcher_host.h"
-#include "content/browser/renderer_host/media/midi_host.h"
 #include "content/browser/renderer_host/media/peer_connection_tracker_host.h"
 #include "content/browser/renderer_host/media/video_capture_host.h"
 #include "content/browser/renderer_host/memory_benchmark_message_filter.h"
@@ -605,8 +604,6 @@ void RenderProcessHostImpl::CreateMessageFilters() {
       GetID(), audio_manager,
       BrowserMainLoop::GetInstance()->audio_mirroring_manager(),
       media_internals, media_stream_manager));
-  channel_->AddFilter(
-      new MIDIHost(BrowserMainLoop::GetInstance()->midi_manager()));
   channel_->AddFilter(new VideoCaptureHost(media_stream_manager));
   channel_->AddFilter(new AppCacheDispatcherHost(
       storage_partition_impl_->GetAppCacheService(),
diff --git a/content/common/content_message_generator.h b/content/common/content_message_generator.h
index 35927dd..2a54f56 100644
--- a/content/common/content_message_generator.h
+++ b/content/common/content_message_generator.h
@@ -31,7 +31,6 @@
 #include "content/common/input_messages.h"
 #include "content/common/java_bridge_messages.h"
 #include "content/common/media/audio_messages.h"
-#include "content/common/media/midi_messages.h"
 #if defined(OS_ANDROID)
 #include "content/common/media/media_player_messages_android.h"
 #endif
diff --git a/content/common/media/midi_messages.h b/content/common/media/midi_messages.h
deleted file mode 100644
index de3cca6..0000000
--- a/content/common/media/midi_messages.h
+++ /dev/null
@@ -1,46 +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.
-
-// IPC messages for access to MIDI hardware.
-// Multiply-included message file, hence no include guard.
-
-#include "base/basictypes.h"
-#include "content/common/content_export.h"
-#include "ipc/ipc_message_macros.h"
-#include "media/midi/midi_port_info.h"
-
-#undef IPC_MESSAGE_EXPORT
-#define IPC_MESSAGE_EXPORT CONTENT_EXPORT
-#define IPC_MESSAGE_START MIDIMsgStart
-
-IPC_STRUCT_TRAITS_BEGIN(media::MIDIPortInfo)
-  IPC_STRUCT_TRAITS_MEMBER(id)
-  IPC_STRUCT_TRAITS_MEMBER(manufacturer)
-  IPC_STRUCT_TRAITS_MEMBER(name)
-  IPC_STRUCT_TRAITS_MEMBER(version)
-IPC_STRUCT_TRAITS_END()
-
-// Renderer request to browser for access to MIDI services.
-IPC_MESSAGE_CONTROL2(MIDIHostMsg_RequestAccess,
-                     int /* client id */,
-                     int /* access */)
-
-IPC_MESSAGE_CONTROL3(MIDIHostMsg_SendData,
-                     int /* port */,
-                     std::vector<uint8> /* data */,
-                     double /* timestamp */)
-
-// Messages sent from the browser to the renderer.
-
-IPC_MESSAGE_CONTROL5(MIDIMsg_AccessApproved,
-                     int /* client id */,
-                     int /* access */,
-                     bool /* success */,
-                     media::MIDIPortInfoList /* input ports */,
-                     media::MIDIPortInfoList /* output ports */)
-
-IPC_MESSAGE_CONTROL3(MIDIMsg_DataReceived,
-                     int /* port */,
-                     std::vector<uint8> /* data */,
-                     double /* timestamp */)
diff --git a/content/content_browser.gypi b/content/content_browser.gypi
index 1984709..c7425fb 100644
--- a/content/content_browser.gypi
+++ b/content/content_browser.gypi
@@ -791,8 +791,6 @@
     'browser/renderer_host/media/media_stream_requester.h',
     'browser/renderer_host/media/media_stream_ui_proxy.cc',
     'browser/renderer_host/media/media_stream_ui_proxy.h',
-    'browser/renderer_host/media/midi_host.cc',
-    'browser/renderer_host/media/midi_host.h',
     'browser/renderer_host/media/video_capture_buffer_pool.cc',
     'browser/renderer_host/media/video_capture_buffer_pool.h',
     'browser/renderer_host/media/video_capture_controller.cc',
diff --git a/content/content_common.gypi b/content/content_common.gypi
index 1ed029b..29b6e07 100644
--- a/content/content_common.gypi
+++ b/content/content_common.gypi
@@ -265,7 +265,6 @@
     'common/media/media_stream_messages.h',
     'common/media/media_stream_options.cc',
     'common/media/media_stream_options.h',
-    'common/media/midi_messages.h',
     'common/media/video_capture.h',
     'common/media/video_capture_messages.h',
     'common/memory_benchmark_messages.h',
diff --git a/content/content_renderer.gypi b/content/content_renderer.gypi
index 24cd543b..c8e52fd 100644
--- a/content/content_renderer.gypi
+++ b/content/content_renderer.gypi
@@ -156,8 +156,6 @@
     'renderer/media/media_stream_dispatcher.h',
     'renderer/media/media_stream_dispatcher_eventhandler.h',
     'renderer/media/media_stream_impl.h',
-    'renderer/media/midi_message_filter.cc',
-    'renderer/media/midi_message_filter.h',
     'renderer/media/pepper_platform_video_decoder_impl.cc',
     'renderer/media/pepper_platform_video_decoder_impl.h',
     'renderer/media/render_media_log.cc',
@@ -166,8 +164,6 @@
     'renderer/media/renderer_gpu_video_decoder_factories.h',
     'renderer/media/renderer_webaudiodevice_impl.cc',
     'renderer/media/renderer_webaudiodevice_impl.h',
-    'renderer/media/renderer_webmidiaccessor_impl.cc',
-    'renderer/media/renderer_webmidiaccessor_impl.h',
     'renderer/media/rtc_video_renderer.cc',
     'renderer/media/rtc_video_renderer.h',
     'renderer/media/stream_texture_factory_impl_android.cc',
diff --git a/content/renderer/media/midi_message_filter.cc b/content/renderer/media/midi_message_filter.cc
deleted file mode 100644
index 1abb537..0000000
--- a/content/renderer/media/midi_message_filter.cc
+++ /dev/null
@@ -1,199 +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.
-
-#include "content/renderer/media/midi_message_filter.h"
-
-#include "base/bind.h"
-#include "base/debug/trace_event.h"
-#include "base/message_loop/message_loop_proxy.h"
-#include "base/strings/utf_string_conversions.h"
-#include "content/common/media/midi_messages.h"
-#include "content/renderer/render_thread_impl.h"
-#include "ipc/ipc_logging.h"
-
-using media::MIDIPortInfoList;
-using base::AutoLock;
-
-namespace content {
-
-MIDIMessageFilter::MIDIMessageFilter(
-    const scoped_refptr<base::MessageLoopProxy>& io_message_loop)
-    : channel_(NULL),
-      io_message_loop_(io_message_loop),
-      next_available_id_(0) {
-}
-
-MIDIMessageFilter::~MIDIMessageFilter() {}
-
-void MIDIMessageFilter::Send(IPC::Message* message) {
-  DCHECK(io_message_loop_->BelongsToCurrentThread());
-  if (!channel_) {
-    delete message;
-  } else {
-    channel_->Send(message);
-  }
-}
-
-bool MIDIMessageFilter::OnMessageReceived(const IPC::Message& message) {
-  DCHECK(io_message_loop_->BelongsToCurrentThread());
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(MIDIMessageFilter, message)
-    IPC_MESSAGE_HANDLER(MIDIMsg_AccessApproved, OnAccessApproved)
-    IPC_MESSAGE_HANDLER(MIDIMsg_DataReceived, OnDataReceived)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
-}
-
-void MIDIMessageFilter::OnFilterAdded(IPC::Channel* channel) {
-  DCHECK(io_message_loop_->BelongsToCurrentThread());
-  channel_ = channel;
-}
-
-void MIDIMessageFilter::OnFilterRemoved() {
-  DCHECK(io_message_loop_->BelongsToCurrentThread());
-
-  // Once removed, a filter will not be used again.  At this time all
-  // delegates must be notified so they release their reference.
-  OnChannelClosing();
-}
-
-void MIDIMessageFilter::OnChannelClosing() {
-  DCHECK(io_message_loop_->BelongsToCurrentThread());
-  channel_ = NULL;
-}
-
-void MIDIMessageFilter::RequestAccess(
-    WebKit::WebMIDIAccessorClient* client, int access) {
-  // Generate and keep track of a "client id" which is sent to the browser
-  // to ask permission to talk to MIDI hardware.
-  // This id is handed back when we receive the answer in OnAccessApproved().
-  if (clients_.find(client) == clients_.end()) {
-    int client_id = next_available_id_++;
-    clients_[client] = client_id;
-
-    io_message_loop_->PostTask(FROM_HERE,
-        base::Bind(&MIDIMessageFilter::RequestAccessOnIOThread, this,
-                   client_id, access));
-  }
-}
-
-void MIDIMessageFilter::RequestAccessOnIOThread(int client_id, int access) {
-  Send(new MIDIHostMsg_RequestAccess(client_id, access));
-}
-
-void MIDIMessageFilter::RemoveClient(WebKit::WebMIDIAccessorClient* client) {
-  ClientsMap::iterator i = clients_.find(client);
-  if (i != clients_.end())
-    clients_.erase(i);
-}
-
-// Received from browser.
-
-void MIDIMessageFilter::OnAccessApproved(
-    int client_id,
-    int access,
-    bool success,
-    MIDIPortInfoList inputs,
-    MIDIPortInfoList outputs) {
-  // Handle on the main JS thread.
-  ChildThread::current()->message_loop()->PostTask(FROM_HERE,
-      base::Bind(&MIDIMessageFilter::HandleAccessApproved, this,
-                 client_id, access, success, inputs, outputs));
-}
-
-void MIDIMessageFilter::HandleAccessApproved(
-    int client_id,
-    int access,
-    bool success,
-    MIDIPortInfoList inputs,
-    MIDIPortInfoList outputs) {
-  WebKit::WebMIDIAccessorClient* client = GetClientFromId(client_id);
-  if (!client)
-    return;
-
-  if (success) {
-    // Add the client's input and output ports.
-    for (size_t i = 0; i < inputs.size(); ++i) {
-      client->didAddInputPort(
-          UTF8ToUTF16(inputs[i].id),
-          UTF8ToUTF16(inputs[i].manufacturer),
-          UTF8ToUTF16(inputs[i].name),
-          UTF8ToUTF16(inputs[i].version));
-    }
-
-    for (size_t i = 0; i < outputs.size(); ++i) {
-      client->didAddOutputPort(
-          UTF8ToUTF16(outputs[i].id),
-          UTF8ToUTF16(outputs[i].manufacturer),
-          UTF8ToUTF16(outputs[i].name),
-          UTF8ToUTF16(outputs[i].version));
-    }
-  }
-
-  if (success)
-    client->didAllowAccess();
-  else
-    client->didBlockAccess();
-}
-
-WebKit::WebMIDIAccessorClient*
-MIDIMessageFilter::GetClientFromId(int client_id) {
-  // Iterating like this seems inefficient, but in practice there generally
-  // will be very few clients (usually one).  Additionally, this lookup
-  // usually happens one time during page load. So the performance hit is
-  // negligible.
-  for (ClientsMap::iterator i = clients_.begin(); i != clients_.end(); ++i) {
-    if ((*i).second == client_id)
-      return (*i).first;
-  }
-  return NULL;
-}
-
-void MIDIMessageFilter::OnDataReceived(int port,
-                                       const std::vector<uint8>& data,
-                                       double timestamp) {
-  TRACE_EVENT0("midi", "MIDIMessageFilter::OnDataReceived");
-
-  ChildThread::current()->message_loop()->PostTask(FROM_HERE,
-      base::Bind(&MIDIMessageFilter::HandleDataReceived, this,
-                 port, data, timestamp));
-}
-
-void MIDIMessageFilter::HandleDataReceived(int port,
-                                           const std::vector<uint8>& data,
-                                           double timestamp) {
-  TRACE_EVENT0("midi", "MIDIMessageFilter::HandleDataReceived");
-
-#if defined(OS_ANDROID)
-  // TODO(crogers): figure out why data() method does not compile on Android.
-  NOTIMPLEMENTED();
-#else
-  for (ClientsMap::iterator i = clients_.begin(); i != clients_.end(); ++i)
-    (*i).first->didReceiveMIDIData(port, data.data(), data.size(), timestamp);
-#endif
-}
-
-void MIDIMessageFilter::SendMIDIData(int port,
-                                     const uint8* data,
-                                     size_t length,
-                                     double timestamp) {
-  // TODO(crogers): we need more work to check the amount of data sent,
-  // throttle if necessary, and filter out the SYSEX messages if not
-  // approved. For now, we will not implement the sending of MIDI data.
-  NOTIMPLEMENTED();
-  // std::vector<uint8> v(data, data + length);
-  // io_message_loop_->PostTask(FROM_HERE,
-  //     base::Bind(&MIDIMessageFilter::SendMIDIDataOnIOThread, this,
-  //                port, v, timestamp));
-}
-
-void MIDIMessageFilter::SendMIDIDataOnIOThread(int port,
-                                               const std::vector<uint8>& data,
-                                               double timestamp) {
-  // Send to the browser.
-  Send(new MIDIHostMsg_SendData(port, data, timestamp));
-}
-
-}  // namespace content
diff --git a/content/renderer/media/midi_message_filter.h b/content/renderer/media/midi_message_filter.h
deleted file mode 100644
index 236ae47..0000000
--- a/content/renderer/media/midi_message_filter.h
+++ /dev/null
@@ -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_
diff --git a/content/renderer/media/renderer_webmidiaccessor_impl.cc b/content/renderer/media/renderer_webmidiaccessor_impl.cc
deleted file mode 100644
index 0a8b68f..0000000
--- a/content/renderer/media/renderer_webmidiaccessor_impl.cc
+++ /dev/null
@@ -1,43 +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.
-
-#include "content/renderer/media/renderer_webmidiaccessor_impl.h"
-
-#include "base/logging.h"
-#include "content/renderer/media/midi_message_filter.h"
-#include "content/renderer/render_thread_impl.h"
-
-namespace content {
-
-RendererWebMIDIAccessorImpl::RendererWebMIDIAccessorImpl(
-    WebKit::WebMIDIAccessorClient* client)
-    : client_(client) {
-  DCHECK(client_);
-}
-
-RendererWebMIDIAccessorImpl::~RendererWebMIDIAccessorImpl() {
-  midi_message_filter()->RemoveClient(client_);
-}
-
-void RendererWebMIDIAccessorImpl::requestAccess(bool access) {
-  midi_message_filter()->RequestAccess(client_, access ? 1 : 0);
-}
-
-void RendererWebMIDIAccessorImpl::sendMIDIData(
-    unsigned port_index,
-    const unsigned char* data,
-    size_t length,
-    double timestamp) {
-  midi_message_filter()->SendMIDIData(
-      port_index,
-      data,
-      length,
-      timestamp);
-}
-
-MIDIMessageFilter* RendererWebMIDIAccessorImpl::midi_message_filter() {
-  return RenderThreadImpl::current()->midi_message_filter();
-}
-
-}  // namespace content
diff --git a/content/renderer/media/renderer_webmidiaccessor_impl.h b/content/renderer/media/renderer_webmidiaccessor_impl.h
deleted file mode 100644
index a6a07c9..0000000
--- a/content/renderer/media/renderer_webmidiaccessor_impl.h
+++ /dev/null
@@ -1,41 +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_RENDERER_WEBMIDIACCESSOR_IMPL_H_
-#define CONTENT_RENDERER_MEDIA_RENDERER_WEBMIDIACCESSOR_IMPL_H_
-
-#include "base/basictypes.h"
-#include "base/compiler_specific.h"
-#include "third_party/WebKit/public/platform/WebMIDIAccessor.h"
-#include "third_party/WebKit/public/platform/WebMIDIAccessorClient.h"
-
-namespace content {
-
-class MIDIMessageFilter;
-
-class RendererWebMIDIAccessorImpl
-    : public WebKit::WebMIDIAccessor {
- public:
-  explicit RendererWebMIDIAccessorImpl(
-      WebKit::WebMIDIAccessorClient* client);
-  virtual ~RendererWebMIDIAccessorImpl();
-
-  // WebKit::WebMIDIAccessor implementation.
-  virtual void requestAccess(bool access) OVERRIDE;
-  virtual void sendMIDIData(unsigned port_index,
-                            const unsigned char* data,
-                            size_t length,
-                            double timestamp) OVERRIDE;
-
- private:
-  WebKit::WebMIDIAccessorClient* client_;
-
-  MIDIMessageFilter* midi_message_filter();
-
-  DISALLOW_COPY_AND_ASSIGN(RendererWebMIDIAccessorImpl);
-};
-
-}  // namespace content
-
-#endif  // CONTENT_RENDERER_MEDIA_RENDERER_WEBMIDIACCESSOR_IMPL_H_
diff --git a/content/renderer/render_thread_impl.cc b/content/renderer/render_thread_impl.cc
index 72e7fb5..795a92a 100644
--- a/content/renderer/render_thread_impl.cc
+++ b/content/renderer/render_thread_impl.cc
@@ -65,7 +65,6 @@
 #include "content/renderer/media/audio_renderer_mixer_manager.h"
 #include "content/renderer/media/media_stream_center.h"
 #include "content/renderer/media/media_stream_dependency_factory.h"
-#include "content/renderer/media/midi_message_filter.h"
 #include "content/renderer/media/peer_connection_tracker.h"
 #include "content/renderer/media/video_capture_impl_manager.h"
 #include "content/renderer/media/video_capture_message_filter.h"
@@ -369,9 +368,6 @@ void RenderThreadImpl::Init() {
   audio_message_filter_ = new AudioMessageFilter(GetIOMessageLoopProxy());
   AddFilter(audio_message_filter_.get());
 
-  midi_message_filter_ = new MIDIMessageFilter(GetIOMessageLoopProxy());
-  AddFilter(midi_message_filter_.get());
-
   AddFilter(new IndexedDBMessageFilter);
 
   GetContentClient()->renderer()->RenderThreadStarted();
diff --git a/content/renderer/render_thread_impl.h b/content/renderer/render_thread_impl.h
index 9ef7002..63cc80c 100644
--- a/content/renderer/render_thread_impl.h
+++ b/content/renderer/render_thread_impl.h
@@ -81,7 +81,6 @@ class InputEventFilter;
 class InputHandlerManager;
 class MediaStreamCenter;
 class MediaStreamDependencyFactory;
-class MIDIMessageFilter;
 class P2PSocketDispatcher;
 class PeerConnectionTracker;
 class RendererWebKitPlatformSupportImpl;
@@ -228,9 +227,6 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
     return audio_message_filter_.get();
   }
 
-  MIDIMessageFilter* midi_message_filter() {
-    return midi_message_filter_.get();
-  }
 
   // Creates the embedder implementation of WebMediaStreamCenter.
   // The resulting object is owned by WebKit and deleted by WebKit at tear-down.
@@ -383,7 +379,6 @@ class CONTENT_EXPORT RenderThreadImpl : public RenderThread,
   scoped_refptr<DBMessageFilter> db_message_filter_;
   scoped_refptr<AudioInputMessageFilter> audio_input_message_filter_;
   scoped_refptr<AudioMessageFilter> audio_message_filter_;
-  scoped_refptr<MIDIMessageFilter> midi_message_filter_;
   scoped_refptr<DevToolsAgentFilter> devtools_agent_message_filter_;
 
   scoped_ptr<MediaStreamDependencyFactory> media_stream_factory_;
diff --git a/content/renderer/renderer_webkitplatformsupport_impl.cc b/content/renderer/renderer_webkitplatformsupport_impl.cc
index 0ec76a1..5e74dc4 100644
--- a/content/renderer/renderer_webkitplatformsupport_impl.cc
+++ b/content/renderer/renderer_webkitplatformsupport_impl.cc
@@ -31,7 +31,6 @@
 #include "content/renderer/hyphenator/hyphenator.h"
 #include "content/renderer/media/media_stream_dependency_factory.h"
 #include "content/renderer/media/renderer_webaudiodevice_impl.h"
-#include "content/renderer/media/renderer_webmidiaccessor_impl.h"
 #include "content/renderer/media/webcontentdecryptionmodule_impl.h"
 #include "content/renderer/render_thread_impl.h"
 #include "content/renderer/renderer_clipboard_client.h"
@@ -92,7 +91,6 @@ using WebKit::WebFileSystem;
 using WebKit::WebFrame;
 using WebKit::WebGamepads;
 using WebKit::WebIDBFactory;
-using WebKit::WebMIDIAccessor;
 using WebKit::Platform;
 using WebKit::WebMediaStreamCenter;
 using WebKit::WebMediaStreamCenterClient;
@@ -773,14 +771,6 @@ RendererWebKitPlatformSupportImpl::createContentDecryptionModule(
 
 //------------------------------------------------------------------------------
 
-WebKit::WebMIDIAccessor*
-RendererWebKitPlatformSupportImpl::createMIDIAccessor(
-    WebKit::WebMIDIAccessorClient* client) {
-  return new RendererWebMIDIAccessorImpl(client);
-}
-
-//------------------------------------------------------------------------------
-
 WebKit::WebString
 RendererWebKitPlatformSupportImpl::signedPublicKeyAndChallengeString(
     unsigned key_size_index,
diff --git a/content/renderer/renderer_webkitplatformsupport_impl.h b/content/renderer/renderer_webkitplatformsupport_impl.h
index 83990c4..104cd24 100644
--- a/content/renderer/renderer_webkitplatformsupport_impl.h
+++ b/content/renderer/renderer_webkitplatformsupport_impl.h
@@ -107,8 +107,6 @@ class CONTENT_EXPORT RendererWebKitPlatformSupportImpl
 
   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&);