[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 2ed9f5be5608ef4dc3b408a5e522e0a9a4387154..46df2e8246dfdbe493bb42db70cd8d6dd2c1d7b5 100644
--- a/Source/devtools/front_end/Target.js
+++ b/Source/devtools/front_end/Target.js
@@ -17,6 +17,10 @@ WebInspector.Target = function(connection, callback)
     this.isMainFrontend = false;
 
     this.pageAgent().canScreencast(this._initializeCapability.bind(this, "canScreencast", null));
+
+    if (WebInspector.experimentsSettings.powerProfiler.isEnabled())
+        this.powerAgent().canProfilePower(this._initializeCapability.bind(this, "canProfilePower", null));
+
     this.workerAgent().canInspectWorkers(this._initializeCapability.bind(this, "isMainFrontend", this._loadedWithCapabilities.bind(this, callback)));
 }
 
@@ -65,6 +69,9 @@ WebInspector.Target.prototype = {
         if (!WebInspector.workerManager)
             WebInspector.workerManager = this.workerManager;
 
+        if (this.canProfilePower)
+            WebInspector.powerProfiler = new WebInspector.PowerProfiler();
+
         if (callback)
             callback(this);
     },