WebRTCStats added, retaining type info when surfacing WebRTC stats into Blink

chrome/test/data/webrtc/peerconnection.js

 /**
  * Copyright 2014 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 /**
  * The one and only peer connection in this page.
  * @private
  */
@@ skipping 271 matching lines @@
   returnToTest('ok-muted');
 }
 
 /**
  * Returns
  */
 function hasSeenCryptoInSdp() {
   returnToTest(gHasSeenCryptoInSdp);
 }
 
+/**
+ * Verifies that |RTCPeerConnection.getStats| returns stats.
+ *
+ * Returns ok-got-stats on success.
+ */
+function verifyStatsGenerated() {
+  peerConnection_().getStats(
+    function(response) {
+      var reports = response.result();
+      var numStats = 0;
+      for (var i = 0; i < reports.length; i++) {
+        var statNames = reports[i].names();
+        numStats += statNames.length;
+        for (var j = 0; j < statNames.length; j++) {
+          var statValue = reports[i].stat(statNames[j]);
+          if (typeof statValue !== 'string')

[tommi (sloooow) - chröme, 2016/07/27 18:38:40]

!= should be enough.  !== is used to do equality+type checks.  The typeof
operator always returns a string, so verifying the return type of 'typeof' is
misleading.  It's actually not about checking statValue.

[hbos_chromium, 2016/07/28 08:27:45]

Done.

+            throw failTest('A stat was returned that is not a string.');
+        }
+      }
+      if (numStats === 0)
+        throw failTest('No stats was returned by getStats.');
+      returnToTest('ok-got-stats');
+    });
+}
+
 // Internals.
 
 /** @private */
 function createPeerConnection_(rtcConfig) {
   try {
     peerConnection = new RTCPeerConnection(rtcConfig, {});
   } catch (exception) {
     throw failTest('Failed to create peer connection: ' + exception);
   }
   peerConnection.onaddstream = addStreamCallback_;
@@ skipping 47 matching lines @@
 function parseJson_(json) {
   // Escape since the \r\n in the SDP tend to get unescaped.
   jsonWithEscapedLineBreaks = json.replace(/\r\n/g, '\\r\\n');
   try {
     return JSON.parse(jsonWithEscapedLineBreaks);
   } catch (exception) {
     failTest('Failed to parse JSON: ' + jsonWithEscapedLineBreaks + ', got ' +
              exception);
   }
 }