iOS: Add ability to specify audio constraints.

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCMediaSource.h

 /*
- *  Copyright 2015 The WebRTC project authors. All Rights Reserved.
+ *  Copyright 2016 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 <Foundation/Foundation.h>
 
 #import <WebRTC/RTCMacros.h>
 
 typedef NS_ENUM(NSInteger, RTCSourceState) {
   RTCSourceStateInitializing,
   RTCSourceStateLive,
   RTCSourceStateEnded,
   RTCSourceStateMuted,
 };
 
 NS_ASSUME_NONNULL_BEGIN
 
 RTC_EXPORT
-@interface RTCVideoSource : NSObject
+@interface RTCMediaSource : NSObject
 
-/** The current state of the RTCVideoSource. */
+/** The current state of the RTCMediaSource. */
 @property(nonatomic, readonly) RTCSourceState state;
 
 - (instancetype)init NS_UNAVAILABLE;
 
 @end
 
 NS_ASSUME_NONNULL_END