Fixes WebRTC browsertests.

content/test/data/media/getusermedia.html

Index: content/test/data/media/getusermedia.html
diff --git a/content/test/data/media/getusermedia.html b/content/test/data/media/getusermedia.html
index f12767173523f7b5aa145649e7c007c5aeba00a8..f194e1a57d98329a45543d087e5c669345e7254b 100644
--- a/content/test/data/media/getusermedia.html
+++ b/content/test/data/media/getusermedia.html
@@ -13,7 +13,16 @@
   function getSources() {
     MediaStreamTrack.getSources(function(devices) {
       document.title = 'Media devices available';
-      sendValueToTest(JSON.stringify(devices));
+      var results = [];
+      for (var device, i = 0; device = devices[i]; ++i) {
+        results.push({
+          'id': device.id,
+          'kind': device.kind,
+          'label': device.label,
+          'facing': device.facing
+        });
+      }
+      sendValueToTest(JSON.stringify(results));
     });
   }