Update API for Objective-C RTCMediaStream.

webrtc/api/objc/RTCMediaStream+Private.h

Index: webrtc/api/objc/RTCMediaStream+Private.h
diff --git a/webrtc/api/objc/RTCAudioTrack+Private.h b/webrtc/api/objc/RTCMediaStream+Private.h
similarity index 55%
copy from webrtc/api/objc/RTCAudioTrack+Private.h
copy to webrtc/api/objc/RTCMediaStream+Private.h
index 36f72c7f2560d775d4e120303173ade21487b259..2c2662b6fa7a86fbd3891da3c0a97305062c9574 100644
--- a/webrtc/api/objc/RTCAudioTrack+Private.h
+++ b/webrtc/api/objc/RTCMediaStream+Private.h
@@ -8,17 +8,24 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-#import "RTCAudioTrack.h"
+#import "RTCMediaStream.h"
 
 #include "talk/app/webrtc/mediastreaminterface.h"
 
 NS_ASSUME_NONNULL_BEGIN
 
-@interface RTCAudioTrack ()
+@interface RTCMediaStream ()
 
-/** AudioTrackInterface created or passed in at construction. */
+/**
+ * MediaStreamInterface representation of this RTCMediaStream object. This is
+ * needed to pass to the underlying C++ APIs.
+ */
 @property(nonatomic, readonly)
-    rtc::scoped_refptr<webrtc::AudioTrackInterface> nativeAudioTrack;
+    rtc::scoped_refptr<webrtc::MediaStreamInterface> nativeMediaStream;
+
+/** Initialize an RTCMediaStream from a native MediaStreamInterface. */
+- (instancetype)initWithNativeMediaStream:
+    (rtc::scoped_refptr<webrtc::MediaStreamInterface>)nativeMediaStream;
 
 @end