Replace MessageLoopProxy with SingleThreadTaskRunner for the rest of media/.

media/video/capture/mac/video_capture_device_mac.h

Index: media/video/capture/mac/video_capture_device_mac.h
diff --git a/media/video/capture/mac/video_capture_device_mac.h b/media/video/capture/mac/video_capture_device_mac.h
index 474e7e1bf450fdd30670794a248332fd7c8a4745..b672409b8c36b5f6307f181a30f8b3946e9496b5 100644
--- a/media/video/capture/mac/video_capture_device_mac.h
+++ b/media/video/capture/mac/video_capture_device_mac.h
@@ -14,12 +14,15 @@
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/message_loop/message_loop_proxy.h"
 #include "media/video/capture/video_capture_device.h"
 #include "media/video/capture/video_capture_types.h"
 
 @protocol PlatformVideoCapturingMac;
 
+namespace base {
+class SingleThreadTaskRunner;
+}
+
 namespace media {
 
 // Called by VideoCaptureManager to open, close and start, stop video capture
@@ -66,7 +69,7 @@ class VideoCaptureDeviceMac : public VideoCaptureDevice {
   bool tried_to_square_pixels_;
 
   // Only read and write state_ from inside this loop.
-  const scoped_refptr<base::MessageLoopProxy> loop_proxy_;
+  const scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   InternalState state_;
 
   // Used with Bind and PostTask to ensure that methods aren't called