Remove platform_video_capturing_mac and the callback thread checker in VideoCaptureDeviceAVFoundati…

media/capture/video/mac/platform_video_capturing_mac.h

-// Copyright 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.
-
-#ifndef MEDIA_CAPTURE_VIDEO_MAC_PLATFORM_VIDEO_CAPTURING_MAC_H_
-#define MEDIA_CAPTURE_VIDEO_MAC_PLATFORM_VIDEO_CAPTURING_MAC_H_
-
-#import <Foundation/Foundation.h>
-
-namespace media {
-class VideoCaptureDeviceMac;
-}
-
-// Protocol representing platform-dependent video capture on Mac.
-@protocol PlatformVideoCapturingMac<NSObject>
-
-// This method initializes the instance by calling NSObject |init| and registers
-// internally a frame receiver at the same time. The frame receiver is supposed
-// to be initialised before and outlive the VideoCapturingDeviceMac
-// implementation.
-- (id)initWithFrameReceiver:(media::VideoCaptureDeviceMac*)frameReceiver;
-
-// Sets the frame receiver. This method executes the registration in mutual
-// exclusion.
-// TODO(mcasas): This method and stopCapture() are always called in sequence and
-// this one is only used to clear the frameReceiver, investigate if both can be
-// merged.
-- (void)setFrameReceiver:(media::VideoCaptureDeviceMac*)frameReceiver;
-
-// Sets which capture device to use by name passed as deviceId argument. The
-// device names are usually obtained via VideoCaptureDevice::GetDeviceNames()
-// method. This method will also configure all device properties except those in
-// setCaptureHeight:width:frameRate. If |deviceId| is nil, capture is stopped
-// and all potential configuration is torn down. Returns YES on success, NO
-// otherwise.
-- (BOOL)setCaptureDevice:(NSString*)deviceId;
-
-// Configures the capture properties.
-- (BOOL)setCaptureHeight:(int)height
-                   width:(int)width
-               frameRate:(float)frameRate;
-
-// Starts video capturing, registers observers. Returns YES on success, NO
-// otherwise.
-- (BOOL)startCapture;
-
-// Stops video capturing, unregisters observers.
-- (void)stopCapture;
-
-@end
-
-#endif  // MEDIA_CAPTURE_VIDEO_MAC_PLATFORM_VIDEO_CAPTURING_MAC_H_