Add thread safety to AudioManagerBase to protect access to the audio thread member variable.

content/test/webrtc_audio_device_test.cc

 // Copyright (c) 2011 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/test/webrtc_audio_device_test.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
@@ skipping 259 matching lines @@
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP_EX()
 
   EXPECT_TRUE(message_is_ok);
 
   return true;
 }
 
 // Posts a final task to the IO message loop and waits for completion.
 void WebRTCAudioDeviceTest::WaitForIOThreadCompletion() {
-  WaitForMessageLoopCompletion(ChildProcess::current()->io_message_loop());
+  WaitForMessageLoopCompletion(
+      ChildProcess::current()->io_message_loop()->message_loop_proxy());
 }
 
 void WebRTCAudioDeviceTest::WaitForAudioManagerCompletion() {
   if (audio_manager_)
     WaitForMessageLoopCompletion(audio_manager_->GetMessageLoop());
 }
 
-void WebRTCAudioDeviceTest::WaitForMessageLoopCompletion(MessageLoop* loop) {
+void WebRTCAudioDeviceTest::WaitForMessageLoopCompletion(
+    base::MessageLoopProxy* loop) {
   base::WaitableEvent* event = new base::WaitableEvent(false, false);
   loop->PostTask(FROM_HERE, base::Bind(&base::WaitableEvent::Signal,
                  base::Unretained(event)));
   if (event->TimedWait(base::TimeDelta::FromMilliseconds(
           TestTimeouts::action_max_timeout_ms()))) {
     delete event;
   } else {
     // Don't delete the event object in case the message ever gets processed.
     // If we do, we will crash the test process.
     ADD_FAILURE() << "Failed to wait for message loop";
@@ skipping 20 matching lines @@
 WebRTCTransportImpl::~WebRTCTransportImpl() {}
 
 int WebRTCTransportImpl::SendPacket(int channel, const void* data, int len) {
   return network_->ReceivedRTPPacket(channel, data, len);
 }
 
 int WebRTCTransportImpl::SendRTCPPacket(int channel, const void* data,
                                         int len) {
   return network_->ReceivedRTCPPacket(channel, data, len);
 }