Make RTC work on Firefox (mostly).

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 3bb3ec27a797671c48c9f6109aa6f4a086238033..88c8363c053a1efd31def6c4b67a7394267333fa 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -17286,7 +17286,13 @@ class RtcDtmfToneChangeEvent extends Event native "RTCDTMFToneChangeEvent" {
 @Experimental
 class RtcIceCandidate native "RTCIceCandidate" {
   factory RtcIceCandidate(Map dictionary) {
-    return JS('RtcIceCandidate', 'new RTCIceCandidate(#)',
+    // TODO(efortuna): Remove this check if when you can actually construct with
+    // the unprefixed RTCIceCandidate in Firefox (currently both are defined,
+    // but one can't be used as a constructor).
+    var constructorName = JS('RtcIceCandidate', 'window[#]',

[sra1, 2013/05/24 22:53:43]

The JavaScript constructor function is not an instance of RtcIceCandidate.
There is no type for it, so just use ''.

[Emily Fortuna, 2013/05/24 23:47:25]

Done.

+        Device.isFirefox ? '${Device.propertyPrefix}RTCIceCandidate' : 
+        'RTCIceCandidate');
+    return JS('RtcIceCandidate', 'new #(#)', constructorName,
         convertDartToNative_SerializedScriptValue(dictionary));
   }
 
@@ -17346,9 +17352,12 @@ class RtcPeerConnection extends EventTarget native "RTCPeerConnection" {
     // Currently in Firefox some of the RTC elements are defined but throw an
     // error unless the user has specifically enabled them in their
     // about:config. So we have to construct an element to actually test if RTC
-    // is supported at at the given time.
+    // is supported at at the given time. Additionally, Firefox only supports IP

[sra1, 2013/05/24 22:53:43]

s/at at/at/

[Emily Fortuna, 2013/05/24 23:47:25]

Done.

+    // numbers (currently), so we test with a random IP address.
+    // See https://bugzilla.mozilla.org/show_bug.cgi?id=837919 for details.
     try {
-      var c = new RtcPeerConnection({"iceServers": [ {"url":"stun:foo.com"}]});
+      var c = new RtcPeerConnection(
+          {"iceServers": [ {"url":"stun:216.93.246.18"}]});

[sra1, 2013/05/24 22:53:43]

So can this fail when the feature is supported?
What if the network is turned off?
Can we use localhost (or 127.0.0.0)?

[Emily Fortuna, 2013/05/24 23:47:25]

That error message seems extra sketchy. It appears with localhost and also
127.0.0.1, but not with the above IP. However, it's only a "warning", that's
displayed on the console, so I'll make it localhost. It still passes the
"supported" check even though it's not "implemented" yet. But if you put an
invalid string in there, the supported check fails.

       return c is RtcPeerConnection;

[sra1, 2013/05/24 22:53:43]

How would this be false?
The JS call says is is RtcPeerConnection, so this is probably constant-folded to
true.

[Emily Fortuna, 2013/05/24 23:47:25]

Good point. Just now checking if constructing the object throws an error.

     } catch (_) {}
     return false;
@@ -17633,8 +17642,6 @@ class RtcPeerConnection extends EventTarget native "RTCPeerConnection" {
   Stream<Event> get onSignalingStateChange => signalingStateChangeEvent.forTarget(this);
 
 }
-
-
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
@@ -17645,7 +17652,14 @@ class RtcPeerConnection extends EventTarget native "RTCPeerConnection" {
 @Experimental
 class RtcSessionDescription native "RTCSessionDescription" {
   factory RtcSessionDescription(Map dictionary) {
-    return JS('RtcSessionDescription', 'new RTCSessionDescription(#)',
+    // TODO(efortuna): Remove this check if when you can actually construct with
+    // the unprefixed RTCIceCandidate in Firefox (currently both are defined,
+    // but one can't be used as a constructor).

[sra1, 2013/05/24 22:53:43]

I'm not sure what 'this check' refers to.
Looks like a syntax error - has ':' but no '?' and us unused.

[Emily Fortuna, 2013/05/24 23:47:25]

Done.

+    var constructorName = JS('RtcSessionDescription', 'window[#]',

[sra1, 2013/05/24 22:53:43]

JS('', ....)

[Emily Fortuna, 2013/05/24 23:47:25]

Done.

+        '${Device.propertyPrefix}RTCSessionDescription' : 
+        'RTCSessionDescription');
+    return JS('RtcSessionDescription', 
+        'new (RTCSessionDescription || mozRTCSessionDescription)(#)',
         convertDartToNative_SerializedScriptValue(dictionary));
   }