Move RTCVideoSource to webrtc/api/objc.

webrtc/api/objc/RTCVideoSource+Private.h

 /*
  *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#import "RTCMediaSource.h"
+#import "RTCVideoSource.h"
 
-#include "talk/app/webrtc/mediastreaminterface.h"
+#include "talk/app/webrtc/videosourceinterface.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
-@interface RTCMediaSource ()
+@interface RTCVideoSource ()
 
 /**
- * The MediaSourceInterface object passed to this RTCMediaSource during
+ * The VideoSourceInterface object passed to this RTCVideoSource during
  * construction.
  */
 @property(nonatomic, readonly)
-    rtc::scoped_refptr<webrtc::MediaSourceInterface> nativeMediaSource;
+    rtc::scoped_refptr<webrtc::VideoSourceInterface> nativeVideoSource;
 
-/** Initialize an RTCMediaSource from a native MediaSourceInterface. */
-- (instancetype)initWithNativeMediaSource:
-    (rtc::scoped_refptr<webrtc::MediaSourceInterface>)nativeMediaSource
+/** Initialize an RTCVideoSource from a native VideoSourceInterface. */
+- (instancetype)initWithNativeVideoSource:
+    (rtc::scoped_refptr<webrtc::VideoSourceInterface>)nativeVideoSource
     NS_DESIGNATED_INITIALIZER;
 
 + (webrtc::MediaSourceInterface::SourceState)nativeSourceStateForState:
     (RTCSourceState)state;
 
 + (RTCSourceState)sourceStateForNativeState:
     (webrtc::MediaSourceInterface::SourceState)nativeState;
 
 + (NSString *)stringForState:(RTCSourceState)state;
 
 @end
 
 NS_ASSUME_NONNULL_END