Use AggressiveConfiguration as the default configuration in IOS

webrtc/api/peerconnectioninterface.h

Index: webrtc/api/peerconnectioninterface.h
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index 624c67f9cba562bbc111fb79fe80ca2d6eafe31c..24e1207050ede27d3f33382debf1e56a9acf4883 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -247,9 +247,14 @@ class PeerConnectionInterface : public rtc::RefCountInterface {
     // An aggressive configuration that has better performance, although it
     // may be riskier and may need extra support in the application.
     static RTCConfiguration AggressiveConfiguration() {
-      RTCConfiguration config;
-      config.redetermine_role_on_ice_restart = false;
-      return config;
+      return RTCConfiguration(true);
+    }
+
+    RTCConfiguration() = default;
+    RTCConfiguration(bool aggressive) {
+      if (aggressive) {
+        redetermine_role_on_ice_restart = false;
+      }

[pthatcher1, 2016/09/01 07:05:44]

I can understand why you would want to have a constructor with a parameter
instead of a static method.  But could we at least use an enum instead of a
bool?

Then we could have:

RTCConfiguration(AGGRESSIVE)
or
RTCConfiguration(SAFE)

which is much easier to read than RTCConfiguration(true), and gives more
flexibility in the future.  

[honghaiz3, 2016/09/01 16:07:50]

Done.

     }
 
     bool dscp() { return media_config.enable_dscp; }