Adding AecDump functionality to AppRTCDemo for iOS

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCPeerConnectionFactory.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.
  */
 
@@ skipping 11 matching lines @@
 @class RTCPeerConnection;
 @class RTCVideoSource;
 @class RTCVideoTrack;
 @protocol RTCPeerConnectionDelegate;
 
 RTC_EXPORT
 @interface RTCPeerConnectionFactory : NSObject
 
 - (instancetype)init NS_DESIGNATED_INITIALIZER;
 
+- (BOOL) startAecDump:(NSString *)filename;

[tkchin_webrtc, 2016/08/19 17:31:42]

These are part of public APIs. Is this something we want to expose for everyone,
or do we want to make it more private?

The RTCEventLog functions were added to peerconnection directly, should this
follow the same example so all the logging functions can be in one place?

nit: 
- (BOOL)startAecDumpWithFilePath:(NSString *)filePath;

no max size?

[peah-webrtc, 2016/08/23 11:45:15]

I changed this to follow what is done in the Android counterpart to this API
(webrtc/api/android/java/src/org/webrtc/PeerConnectionFactory.java), 
i.e.,
The method takes a file descriptor and a limit, and passes this to the native
code.


I change the max size to be a parameter, but for the app I will pass -1 to
specify that there should be no limit in size for the recording.

+
+- (void)stopAecDump;
+
 /** Initialize an RTCAVFoundationVideoSource with constraints. */
 - (RTCAVFoundationVideoSource *)avFoundationVideoSourceWithConstraints:
     (nullable RTCMediaConstraints *)constraints;
 
 /** Initialize an RTCAudioTrack with an id. */
 - (RTCAudioTrack *)audioTrackWithTrackId:(NSString *)trackId;
 
 /** Initialize an RTCVideoTrack with a source and an id. */
 - (RTCVideoTrack *)videoTrackWithSource:(RTCVideoSource *)source
                                 trackId:(NSString *)trackId;
 
 /** Initialize an RTCMediaStream with an id. */
 - (RTCMediaStream *)mediaStreamWithStreamId:(NSString *)streamId;
 
 /** Initialize an RTCPeerConnection with a configuration, constraints, and
  *  delegate.
  */
 - (RTCPeerConnection *)peerConnectionWithConfiguration:
     (RTCConfiguration *)configuration
                                            constraints:
     (RTCMediaConstraints *)constraints
                                               delegate:
     (nullable id<RTCPeerConnectionDelegate>)delegate;
 
 @end
 
 NS_ASSUME_NONNULL_END