Move the device enumerate/open/close work to device thread from IO thread

content/browser/renderer_host/media/video_capture_manager.cc

Index: content/browser/renderer_host/media/video_capture_manager.cc
diff --git a/content/browser/renderer_host/media/video_capture_manager.cc b/content/browser/renderer_host/media/video_capture_manager.cc
index be5738de38e27da91802d8e2a04467529ce4710b..4d4e5a79e707ae0a364da5ceb422dbf3fe33d1dc 100644
--- a/content/browser/renderer_host/media/video_capture_manager.cc
+++ b/content/browser/renderer_host/media/video_capture_manager.cc
@@ -38,16 +38,15 @@ struct VideoCaptureManager::Controller {
   Handlers handlers;
 };
 
-VideoCaptureManager::VideoCaptureManager()
-  : vc_device_thread_("VideoCaptureManagerThread"),
+VideoCaptureManager::VideoCaptureManager(
+    scoped_refptr<base::MessageLoopProxy> message_loop)
+    : message_loop_(message_loop),
     listener_(NULL),
     new_capture_session_id_(kFirstSessionId),
     use_fake_device_(false) {
-  vc_device_thread_.Start();
 }
 
 VideoCaptureManager::~VideoCaptureManager() {
-  vc_device_thread_.Stop();
   DCHECK(devices_.empty());
   DCHECK(controllers_.empty());
 }
@@ -68,7 +67,7 @@ void VideoCaptureManager::EnumerateDevices() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(listener_);
 
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::OnEnumerateDevices, this));
 }
@@ -80,7 +79,7 @@ int VideoCaptureManager::Open(const StreamDeviceInfo& device) {
   // Generate a new id for this device.
   int video_capture_session_id = new_capture_session_id_++;
 
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::OnOpen, this, video_capture_session_id,
                  device));
@@ -92,7 +91,7 @@ void VideoCaptureManager::Close(int capture_session_id) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(listener_);
 
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::OnClose, this, capture_session_id));
 }
@@ -102,7 +101,7 @@ void VideoCaptureManager::Start(
     media::VideoCaptureDevice::EventHandler* video_capture_receiver) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::OnStart, this, capture_params,
                  video_capture_receiver));
@@ -113,7 +112,7 @@ void VideoCaptureManager::Stop(
     base::Closure stopped_cb) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::OnStop, this, capture_session_id,
                  stopped_cb));
@@ -128,10 +127,6 @@ void VideoCaptureManager::UseFakeDevice() {
   use_fake_device_ = true;
 }
 
-MessageLoop* VideoCaptureManager::GetMessageLoop() {
-  return vc_device_thread_.message_loop();
-}
-
 void VideoCaptureManager::OnEnumerateDevices() {
   DCHECK(IsOnCaptureDeviceThread());
 
@@ -360,7 +355,7 @@ void VideoCaptureManager::PostOnError(int capture_session_id,
 }
 
 bool VideoCaptureManager::IsOnCaptureDeviceThread() const {
-  return MessageLoop::current() == vc_device_thread_.message_loop();
+  return message_loop_->BelongsToCurrentThread();
 }
 
 void VideoCaptureManager::GetAvailableDevices(
@@ -420,7 +415,7 @@ void VideoCaptureManager::AddController(
     VideoCaptureControllerEventHandler* handler,
     base::Callback<void(VideoCaptureController*)> added_cb) {
   DCHECK(handler);
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::DoAddControllerOnDeviceThread,
                  this, capture_params, handler, added_cb));
@@ -452,7 +447,7 @@ void VideoCaptureManager::RemoveController(
     VideoCaptureController* controller,
     VideoCaptureControllerEventHandler* handler) {
   DCHECK(handler);
-  vc_device_thread_.message_loop()->PostTask(
+  message_loop_->PostTask(
       FROM_HERE,
       base::Bind(&VideoCaptureManager::DoRemoveControllerOnDeviceThread, this,
                  make_scoped_refptr(controller), handler));