Add a switch to redetermine role when ICE restarts.

webrtc/api/peerconnectionfactory.h

 /*
  *  Copyright 2011 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 73 matching lines @@
   bool StartRtcEventLog(rtc::PlatformFile file,
                         int64_t max_size_bytes) override {
     return false;
   }
   // TODO(ivoc) Remove after Chrome is updated.
   void StopRtcEventLog() override {}
 
   virtual webrtc::MediaControllerInterface* CreateMediaController(
       const cricket::MediaConfig& config) const;
   virtual cricket::TransportController* CreateTransportController(
-      cricket::PortAllocator* port_allocator);
+      cricket::PortAllocator* port_allocator,
+      bool redetermine_role_on_ice_restart);

[pthatcher1, 2016/08/29 22:18:07]

Can we make this a struct instead of a bool?  Then when we add new things over
time, we just add them to the struct rather than adding more and more arguments.

[honghaiz3, 2016/08/29 23:16:59]

Can we delay using a struct until we need to add a second argument?
The chance is that we may not need a second argument at all, which will make the
struct look weird. 
Plus, I think our plan is to get rid of this argument once we can safely switch
to "not redetermine the role" in Chrome. In fact, I think it might be better to
use a setter method instead of changing the constructor because of this reason,
but we have already made changes to change the constructor.  

[pthatcher1, 2016/08/29 23:27:42]

Good point about removing it soon.  

   virtual rtc::Thread* signaling_thread();
   virtual rtc::Thread* worker_thread();
   virtual rtc::Thread* network_thread();
   const Options& options() const { return options_; }
 
  protected:
   PeerConnectionFactory();
   PeerConnectionFactory(
       rtc::Thread* network_thread,
       rtc::Thread* worker_thread,
@@ skipping 24 matching lines @@
   // External Video decoder factory. This can be NULL if the client has not
   // injected any. In that case, video engine will use the internal SW decoder.
   std::unique_ptr<cricket::WebRtcVideoDecoderFactory> video_decoder_factory_;
   std::unique_ptr<rtc::BasicNetworkManager> default_network_manager_;
   std::unique_ptr<rtc::BasicPacketSocketFactory> default_socket_factory_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_PEERCONNECTIONFACTORY_H_