Refactor some ObjC API init methods.

webrtc/api/objc/RTCPeerConnection.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 99 matching lines @@
 @property(nonatomic, readonly, nullable)
     RTCSessionDescription *localDescription;
 @property(nonatomic, readonly, nullable)
     RTCSessionDescription *remoteDescription;
 @property(nonatomic, readonly) RTCSignalingState signalingState;
 @property(nonatomic, readonly) RTCIceConnectionState iceConnectionState;
 @property(nonatomic, readonly) RTCIceGatheringState iceGatheringState;
 
 - (instancetype)init NS_UNAVAILABLE;
 
-/** Initialize an RTCPeerConnection with a configuration, constraints, and
- *  delegate.
- */
-- (instancetype)initWithFactory:
-    (RTCPeerConnectionFactory *)factory
-                  configuration:
-    (RTCConfiguration *)configuration
-                    constraints:
-    (RTCMediaConstraints *)constraints
-                       delegate:
-    (nullable id<RTCPeerConnectionDelegate>)delegate
-    NS_DESIGNATED_INITIALIZER;
-
 /** Sets the PeerConnection's global configuration to |configuration|.
  *  Any changes to STUN/TURN servers or ICE candidate policy will affect the
  *  next gathering phase, and cause the next call to createOffer to generate
  *  new ICE credentials. Note that the BUNDLE and RTCP-multiplexing policies
  *  cannot be changed with this method.
  */
 - (BOOL)setConfiguration:(RTCConfiguration *)configuration;
 
 /** Terminate all media and close the transport. */
 - (void)close;
@@ skipping 46 matching lines @@
  */
 - (void)statsForTrack:
     (nullable RTCMediaStreamTrack *)mediaStreamTrack
      statsOutputLevel:(RTCStatsOutputLevel)statsOutputLevel
     completionHandler:
     (nullable void (^)(NSArray<RTCStatsReport *> *stats))completionHandler;
 
 @end
 
 NS_ASSUME_NONNULL_END