Add support for RTCConfiguration.iceCandidatePoolSize.

content/test/data/media/peerconnection-setConfiguration.html

Index: content/test/data/media/peerconnection-setConfiguration.html
diff --git a/content/test/data/media/peerconnection-setConfiguration.html b/content/test/data/media/peerconnection-setConfiguration.html
index 9bf30de1e0555fc5129f80b3643eee7bbaf0c37a..8a896c15db4863d6b0d5800d8fcbe47ddc49ddac 100644
--- a/content/test/data/media/peerconnection-setConfiguration.html
+++ b/content/test/data/media/peerconnection-setConfiguration.html
@@ -22,7 +22,12 @@
   function testSetConfiguration() {
     gPeerConnection = new RTCPeerConnection(
         {iceServers:[], iceTransportPolicy:'all', bundlePolicy:'balanced',
-         rtcpMuxPolicy:'require', certificates:[]});
+         rtcpMuxPolicy:'require', certificates:[], iceCandidatePoolSize:0});
+    // Change ICE candidate pool size, which will succeed before
+    // setLocalDescription is called.
+    gPeerConnection.setConfiguration(
+        {iceServers:[], iceTransportPolicy:'all', bundlePolicy:'balanced',
+         rtcpMuxPolicy:'require', certificates:[], iceCandidatePoolSize:1});

[hbos_chromium, 2017/03/03 11:56:06]

(Later when getConfiguration is available we should verify the pool size value
after each setConfiguration. Not a blocker.)

[Taylor_Brandstetter, 2017/03/03 18:44:46]

That's done in Zhi's CL: https://codereview.chromium.org/2706563003/

     // Now test successful cases of setConfiguration. Changes should trigger an
     // ICE restart in the next offer. To do this, first we need to trigger an
     // initial ICE gathering phase and wait until it completes.
@@ -38,7 +43,7 @@
       // Policy changed.
       gPeerConnection.setConfiguration(
           {iceServers:[], iceTransportPolicy:'relay', bundlePolicy:'balanced',
-           rtcpMuxPolicy:'require', certificates:[]});
+           rtcpMuxPolicy:'require', certificates:[], iceCandidatePoolSize:1});
       createOfferAndSetLocalDescription();
     }
   }
@@ -49,7 +54,8 @@
       // Servers changed.
       gPeerConnection.setConfiguration(
           {iceServers:[{urls:'stun:foo.invalid'}], iceTransportPolicy:'all',
-           bundlePolicy:'balanced', rtcpMuxPolicy:'require', certificates:[]});
+           bundlePolicy:'balanced', rtcpMuxPolicy:'require', certificates:[],
+           iceCandidatePoolSize:1});
       createOfferAndSetLocalDescription();
     }
   }
@@ -80,13 +86,13 @@
   function continueTestSetConfigurationErrors() {
     gPeerConnection = new RTCPeerConnection(
         {iceServers:[], iceTransportPolicy:'all', bundlePolicy:'balanced',
-         rtcpMuxPolicy:'require', certificates:[]});
+         rtcpMuxPolicy:'require', certificates:[], iceCandidatePoolSize:1});
     // If bundlePolicy, rtcpMuxPolicy or certificates are changed, an
     // InvalidModificationError should be thrown.
     assertThrows(gPeerConnection.setConfiguration,
                  {iceServers:[], iceTransportPolicy:'all',
                   bundlePolicy:'max-bundle', rtcpMuxPolicy:'require',
-                  certificates:[]});
+                  certificates:[], iceCandidatePoolSize:1});
     assertThrows(gPeerConnection.setConfiguration,
                  {iceServers:[], iceTransportPolicy:'all',
                   bundlePolicy:'balanced', rtcpMuxPolicy:'negotiate',
@@ -94,23 +100,46 @@
     assertThrows(gPeerConnection.setConfiguration,
                  {iceServers:[], iceTransportPolicy:'all',
                   bundlePolicy:'balanced', rtcpMuxPolicy:'require',
-                  certificates:[gCertificate]});
+                  certificates:[gCertificate], iceCandidatePoolSize:1});
     // Failure to parse URL should result in SyntaxError.
     assertThrows(gPeerConnection.setConfiguration,
                  {iceServers:[{url:'stunnnn:foo.invalid'}],
                   iceTransportPolicy:'all', bundlePolicy:'max-bundle',
-                  rtcpMuxPolicy:'require', certificates:[]});
+                  rtcpMuxPolicy:'require', certificates:[],
+                  iceCandidatePoolSize:1});
     // TURN server with missing username should result in InvalidAccessError.
     assertThrows(gPeerConnection.setConfiguration,
                  {iceServers:[{url:'turn:foo.invalid'}],
                   iceTransportPolicy:'all', bundlePolicy:'max-bundle',
-                  rtcpMuxPolicy:'require', certificates:[]});
+                  rtcpMuxPolicy:'require', certificates:[],
+                  iceCandidatePoolSize:1});
     // Sanity check that a configuration can be successfully set, and thus
     // there's not something unexpected causing the above exceptions.
     gPeerConnection.setConfiguration(
         {iceServers:[], iceTransportPolicy:'all', bundlePolicy:'balanced',
-         rtcpMuxPolicy:'require', certificates:[]});
-    reportTestSuccess();
+         rtcpMuxPolicy:'require', certificates:[], iceCandidatePoolSize:1});
+    // Lastly: only after applying a local description, changing the candidate
+    // pool size is not allowed.

[hbos_chromium, 2017/03/03 11:56:06]

Is this spec-compliant? If it isn't but it should be, can you file a bug if
needed?

The latest rawgit spec says: "Set the ICE Agent's prefetched ICE candidate pool
size as defined in [JSEP] (section 3.5.4. and section 4.1.1.) to the value of
configuration.iceCandidatePoolSize. If the new ICE candidate pool size changes
the existing setting, this may result in immediate gathering of new pooled
candidates, or discarding of existing pooled candidates, as defined in [JSEP]
(section 4.1.15.)."

(Latest published spec says: "no action will be taken until the
RTCPeerConnection 's ICE gathering state transitions to gathering. If a script
wants this to happen immediately, it should do an ICE restart.")

I don't see anything about throwing an exception if the value is different after
this event. 

[Taylor_Brandstetter, 2017/03/03 18:44:46]

Yeah, it looks like webrtc-pc is out of sync with JSEP. Filed issue:
https://github.com/w3c/webrtc-pc/issues/1049

+    gPeerConnection.createOffer({offerToReceiveAudio:1})
+      .then(function(offer) {
+        console.log("Setting offer:\n" + offer.sdp);
+        gPeerConnection.setLocalDescription(offer).then(
+          function() {
+            // Pool size absent, which means it should default to 0, which is
+            // different than its current value of 1.
+            assertThrows(gPeerConnection.setConfiguration,
+                         {iceServers:[], iceTransportPolicy:'all',
+                          bundlePolicy:'balanced', rtcpMuxPolicy:'require',
+                          certificates:[]});
+            reportTestSuccess();
+          },
+          function() { failTest('Failed to set local description.') }
+        );
+        },
+        function() {
+          failTest('Failed to generate offer.')
+        }
+      );
   }
 
   function assertThrows(func) {