Preparation CL for WebRTC performance test using promise-based getStats

chrome/test/data/webrtc/peerconnection_getstats.js

 /**
  * Copyright 2016 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.
  */
 
 /**
  * Maps "RTCStats.type" values to descriptions of whitelisted (allowed to be
  * exposed to the web) RTCStats-derived dictionaries described below.
  * @private
@@ skipping 243 matching lines @@
         ids.add(stats.id);
       }
       returnToTest('ok-' + JSON.stringify(Array.from(statsTypes.values())));
     },
     function(e) {
       throw failTest('Promise was rejected: ' + e);
     });
 }
 
 /**
+ * Gets the result of the promise-based |RTCPeerConnection.getStats| as a
+ * dictionary of RTCStats-dictionaries.
+ *
+ * Returns "ok-" followed by a JSON-stringified dictionary of dictionaries to
+ * the test.
+ */
+function getStatsAsDictionary() {
+  peerConnection_().getStats()
+    .then(function(report) {
+      if (report == null || report.size == 0)
+        throw new failTest('report is null or empty.');
+      let reportDictionary = {};
+      for (let stats of report.values()) {
+        reportDictionary[stats.id] = stats;
+      }
+      returnToTest('ok-' + JSON.stringify(reportDictionary, null, '  '));

[hbos_chromium, 2016/11/30 12:38:05]

nit: "null, '  '" does pretty indented JSON, I did this for debugging and forgot
about it, will remove params before landing for compact JSON.

+    },
+    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.
  */
 function getWhitelistedStatsTypes() {
   returnToTest(JSON.stringify(Array.from(gStatsWhitelist.keys())));
 }
 
 // Internals.
 
 /** @private */
@@ skipping 54 matching lines @@
         if (typeof(element) !== elementType) {
           throw failTest('stats.' + propertyName + ' should have a different ' +
               'type according to the whitelist (an element of the array has ' +
               'the incorrect type): ' + JSON.stringify(stats[propertyName]) +
               ' vs ' + whitelistedStats[propertyName]);
         }
       }
     }
   }
 }