Performance measures of old and new RTCPeerConnection.getStats added.

chrome/test/data/webrtc/peerconnection_getstats.js

Index: chrome/test/data/webrtc/peerconnection_getstats.js
diff --git a/chrome/test/data/webrtc/peerconnection_getstats.js b/chrome/test/data/webrtc/peerconnection_getstats.js
index 6054a5cea7c19057127c4ec5898391e570d5ff35..e7718481d5a39f9800de893fee9f509867cc1344 100644
--- a/chrome/test/data/webrtc/peerconnection_getstats.js
+++ b/chrome/test/data/webrtc/peerconnection_getstats.js
@@ -301,6 +301,22 @@ function getStatsReportDictionary() {
 }
 
 /**
+ * Invokes the promise-based |RTCPeerConnection.getStats| and returns to test
+ * when done, not doing anything with the results. For testing performance.
+ *
+ * Returns "done" on success.
+ */
+function getStatsAndReturn() {
+  peerConnection_().getStats()
+    .then(function(report) {
+      returnToTest('done');
+    },
+    function(e) {
+      throw failTest('Promise was rejected: ' + e);
+    });
+}
+
+/**
  * Returns a complete list of whitelisted "RTCStats.type" values as a
  * JSON-stringified array of strings to the test.
  */