[DevTools] Add power profiler and power overview in timeline panel.

Source/devtools/front_end/PowerProfiler.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.
+
+/**
+ * @constructor
+ * @extends {WebInspector.Object}
+ */
+WebInspector.PowerProfiler = function()
+{
+    WebInspector.Object.call(this);
+    this._dispatcher = new WebInspector.PowerDispatcher(this);
+}
+
+WebInspector.PowerProfiler.EventTypes = {
+    PowerEventRecorded: "PowerEventRecorded"
+}
+
+WebInspector.PowerProfiler.prototype = {
+
+    startProfile: function ()
+    {
+        PowerAgent.start();
+    },
+
+    stopProfile: function ()
+    {
+        PowerAgent.end();
+    },
+
+    __proto__: WebInspector.Object.prototype
+}
+
+/**
+ * @constructor
+ * @implements {WebInspector.PowerEventDispatcher}
+ */
+WebInspector.PowerDispatcher = function(profiler)
+{
+    this._profiler = profiler;
+    InspectorBackend.registerPowerDispatcher(this);
+}
+
+WebInspector.PowerDispatcher.prototype = {
+    dataAvailable: function(events)
+    {
+        for (var i in events)
+            this._profiler.dispatchEventToListeners(WebInspector.PowerProfiler.EventTypes.PowerEventRecorded, events[i]);
+    }
+}
+
+/**
+ * @type {!WebInspector.PowerProfiler}
+ */
+WebInspector.powerProfiler;