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

Source/devtools/front_end/Target.js

Index: Source/devtools/front_end/Target.js
diff --git a/Source/devtools/front_end/Target.js b/Source/devtools/front_end/Target.js
index 1dc4c70318e28d6386b7f2e20710e2192ad73245..3df684c9c52b73d89d221e41f676d834163f544c 100644
--- a/Source/devtools/front_end/Target.js
+++ b/Source/devtools/front_end/Target.js
@@ -17,6 +17,7 @@ WebInspector.Target = function(connection, callback)
     this.canInspectWorkers = false;
 
     this.pageAgent().canScreencast(this._initializeCapability.bind(this, "canScreencast", null));
+    this.powerAgent().canProfilePower(this._initializeCapability.bind(this, "canProfilePower", null));
     this.workerAgent().canInspectWorkers(this._initializeCapability.bind(this, "canInspectWorkers", this._loadedWithCapabilities.bind(this, callback)));
 
     // In case of loading as a web page with no bindings / harness, kick off initialization manually.
@@ -59,6 +60,9 @@ WebInspector.Target.prototype = {
         this.workerManager = new WebInspector.WorkerManager(this.canInspectWorkers);
         WebInspector.workerManager = this.workerManager;
 
+        if (WebInspector.experimentsSettings.powerTimeline.isEnabled() && this.canProfilePower)
+            WebInspector.powerProfiler = new WebInspector.PowerProfiler();
+
         if (callback)
             callback(this);
     },