Use a single benchmark for WebRTC telemetry tests.

tools/perf/page_sets/webrtc_track_peerconnections.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.
-
-// This file overwrites the RTCPeerConnection constructor with a new constructor
-// which tracks all created connections. It does this by periodically gathering
-// statistics on all connections, using the WebRTC statistics API. All reports
-// are gathered into window.peerConnectionReports, which contains one list per
-// connection. In each list there is a number of report batches, which in turn
-// contains metric names mapped to values.
-
-window.peerConnectionReports = [];
-
-RTCPeerConnection = webkitRTCPeerConnection = (function() {
-  function getReportsAsDicts(getStatsResult) {
-    var result = [];
-    getStatsResult.forEach(function(report) {
-      var values = {};
-      report.names().forEach(function(name) {
-        values[name] = report.stat(name);
-      });
-      result.push(values);
-    });
-    return result;
-  }
-
-  function gatherStatsFromOneConnection(peerConnection) {
-    var connectionId = window.peerConnectionReports.length;
-    window.peerConnectionReports.push([]);
-    var pollIntervalMs = 1000;
-
-    setInterval(function() {
-      peerConnection.getStats(function(response) {
-        var reports = getReportsAsDicts(response.result());
-        window.peerConnectionReports[connectionId].push(reports);
-      });
-    }, pollIntervalMs);
-  }
-
-  var originalConstructor = RTCPeerConnection;
-  return function() {
-    // Bind the incoming arguments to the original constructor.
-    var args = [null].concat(Array.prototype.slice.call(arguments));
-    var factoryFunction = originalConstructor.bind.apply(
-      originalConstructor, args);
-
-    // Create the object and track it.
-    var peerConnection = new factoryFunction();
-    gatherStatsFromOneConnection(peerConnection);
-    return peerConnection;
-  }
-})();