Replace MessageLoopProxy with SingleThreadTaskRunner for the rest of media/.

media/video/capture/mac/video_capture_device_mac.mm

Index: media/video/capture/mac/video_capture_device_mac.mm
diff --git a/media/video/capture/mac/video_capture_device_mac.mm b/media/video/capture/mac/video_capture_device_mac.mm
index 77d30e9bbe45005ee2112f0bccc80831870f1245..9a2f02da9a5ae1055fa4336108f5a39826e241b0 100644
--- a/media/video/capture/mac/video_capture_device_mac.mm
+++ b/media/video/capture/mac/video_capture_device_mac.mm
@@ -112,7 +112,7 @@ VideoCaptureDeviceMac::VideoCaptureDeviceMac(const Name& device_name)
     : device_name_(device_name),
       sent_frame_info_(false),
       tried_to_square_pixels_(false),
-      loop_proxy_(base::MessageLoopProxy::current()),
+      task_runner_(base::MessageLoopProxy::current()),
       state_(kNotInitialized),
       weak_factory_(this),
       weak_this_(weak_factory_.GetWeakPtr()),
@@ -120,14 +120,14 @@ VideoCaptureDeviceMac::VideoCaptureDeviceMac(const Name& device_name)
 }
 
 VideoCaptureDeviceMac::~VideoCaptureDeviceMac() {
-  DCHECK_EQ(loop_proxy_, base::MessageLoopProxy::current());
+  DCHECK_EQ(task_runner_->BelongsToCurrentThread());
   [capture_device_ release];
 }
 
 void VideoCaptureDeviceMac::AllocateAndStart(
     const VideoCaptureCapability& capture_format,
     scoped_ptr<VideoCaptureDevice::Client> client) {
-  DCHECK_EQ(loop_proxy_, base::MessageLoopProxy::current());
+  DCHECK_EQ(task_runner_->BelongsToCurrentThread());
   if (state_ != kIdle) {
     return;
   }
@@ -184,7 +184,7 @@ void VideoCaptureDeviceMac::AllocateAndStart(
 }
 
 void VideoCaptureDeviceMac::StopAndDeAllocate() {
-  DCHECK_EQ(loop_proxy_, base::MessageLoopProxy::current());
+  DCHECK_EQ(task_runner_->BelongsToCurrentThread());
   DCHECK(state_ == kCapturing || state_ == kError) << state_;
   [capture_device_ stopCapture];
 
@@ -196,7 +196,7 @@ void VideoCaptureDeviceMac::StopAndDeAllocate() {
 }
 
 bool VideoCaptureDeviceMac::Init() {
-  DCHECK_EQ(loop_proxy_, base::MessageLoopProxy::current());
+  DCHECK_EQ(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(state_, kNotInitialized);
 
   Names device_names;
@@ -294,13 +294,13 @@ void VideoCaptureDeviceMac::ReceiveFrame(
 }
 
 void VideoCaptureDeviceMac::ReceiveError(const std::string& reason) {
-  loop_proxy_->PostTask(FROM_HERE,
+  task_runner_->PostTask(FROM_HERE,
       base::Bind(&VideoCaptureDeviceMac::SetErrorState, weak_this_,
           reason));
 }
 
 void VideoCaptureDeviceMac::SetErrorState(const std::string& reason) {
-  DCHECK_EQ(loop_proxy_, base::MessageLoopProxy::current());
+  DCHECK_EQ(task_runner_->BelongsToCurrentThread());
   DLOG(ERROR) << reason;
   state_ = kError;
   client_->OnError();