iOS: Add ability to specify audio constraints.

webrtc/sdk/objc/Framework/Classes/RTCPeerConnectionFactory.mm

 /*
  *  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 "RTCPeerConnectionFactory+Private.h"
 
 #import "NSString+StdString.h"
 #import "RTCAVFoundationVideoSource+Private.h"
+#import "RTCAudioSource+Private.h"
 #import "RTCAudioTrack+Private.h"
+#import "RTCMediaConstraints+Private.h"
 #import "RTCMediaStream+Private.h"
 #import "RTCPeerConnection+Private.h"
 #import "RTCVideoSource+Private.h"
 #import "RTCVideoTrack+Private.h"
 
 @implementation RTCPeerConnectionFactory {
   std::unique_ptr<rtc::Thread> _networkThread;
   std::unique_ptr<rtc::Thread> _workerThread;
   std::unique_ptr<rtc::Thread> _signalingThread;
 }
@@ skipping 28 matching lines @@
   // is passed to the recorder, and the recorder
   // closes the file when needed.
   return _nativeFactory->StartAecDump(fileDescriptor, maxFileSizeInBytes);
 }
 
 - (void)stopAecDump {
   // The file is closed by the call below.
   _nativeFactory->StopAecDump();
 }
 
+- (RTCAudioSource *)audioSourceWithConstraints:(nullable RTCMediaConstraints *)constraints {
+  std::unique_ptr<webrtc::MediaConstraints> nativeConstraints;
+  if (constraints) {
+    nativeConstraints = constraints.nativeConstraints;
+  }
+  rtc::scoped_refptr<webrtc::AudioSourceInterface> source =
+      _nativeFactory->CreateAudioSource(nativeConstraints.get());
+  return [[RTCAudioSource alloc] initWithNativeAudioSource:source];
+}
+
+- (RTCAudioTrack *)audioTrackWithTrackId:(NSString *)trackId {
+  RTCAudioSource *audioSource = [self audioSourceWithConstraints:nil];
+  return [self audioTrackWithSource:audioSource trackId:trackId];
+}
+
+- (RTCAudioTrack *)audioTrackWithSource:(RTCAudioSource *)source
+                                trackId:(NSString *)trackId {
+  return [[RTCAudioTrack alloc] initWithFactory:self
+                                         source:source
+                                        trackId:trackId];
+}
+
 - (RTCAVFoundationVideoSource *)avFoundationVideoSourceWithConstraints:
     (nullable RTCMediaConstraints *)constraints {
   return [[RTCAVFoundationVideoSource alloc] initWithFactory:self
                                                  constraints:constraints];
 }
 
-- (RTCAudioTrack *)audioTrackWithTrackId:(NSString *)trackId {
-  return [[RTCAudioTrack alloc] initWithFactory:self
-                                        trackId:trackId];
-}
-
 - (RTCVideoTrack *)videoTrackWithSource:(RTCVideoSource *)source
                                 trackId:(NSString *)trackId {
   return [[RTCVideoTrack alloc] initWithFactory:self
                                          source:source
                                         trackId:trackId];
 }
 
 - (RTCMediaStream *)mediaStreamWithStreamId:(NSString *)streamId {
   return [[RTCMediaStream alloc] initWithFactory:self
                                         streamId:streamId];
 }
 
 - (RTCPeerConnection *)peerConnectionWithConfiguration:
     (RTCConfiguration *)configuration
                                            constraints:
     (RTCMediaConstraints *)constraints
                                               delegate:
     (nullable id<RTCPeerConnectionDelegate>)delegate {
   return [[RTCPeerConnection alloc] initWithFactory:self
                                       configuration:configuration
                                         constraints:constraints
                                            delegate:delegate];
 }
 
 @end