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

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

Index: trunk/src/content/renderer/media/midi_message_filter.cc
===================================================================
--- trunk/src/content/renderer/media/midi_message_filter.cc	(revision 207994)
+++ trunk/src/content/renderer/media/midi_message_filter.cc	(working copy)
@@ -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