DevTools: do not make main panel unconditionally focused by default.

third_party/WebKit/Source/devtools/front_end/screencast/ScreencastApp.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.
 /**
  * @implements {Common.App}
  * @implements {SDK.TargetManager.Observer}
  * @unrestricted
  */
 Screencast.ScreencastApp = class {
   constructor() {
@@ skipping 21 matching lines @@
     var rootView = new UI.RootView();
 
     this._rootSplitWidget = new UI.SplitWidget(false, true, 'InspectorView.screencastSplitViewState', 300, 300);
     this._rootSplitWidget.setVertical(true);
     this._rootSplitWidget.setSecondIsSidebar(true);
     this._rootSplitWidget.show(rootView.element);
     this._rootSplitWidget.hideMain();
 
     this._rootSplitWidget.setSidebarWidget(UI.inspectorView);
     rootView.attachToDocument(document);
+    rootView.focus();
   }
 
   /**
    * @override
    * @param {!SDK.Target} target
    */
   targetAdded(target) {
     if (this._target)
       return;
     this._target = target;
@@ skipping 67 matching lines @@
  */
 Screencast.ScreencastAppProvider = class {
   /**
    * @override
    * @return {!Common.App}
    */
   createApp() {
     return Screencast.ScreencastApp._instance();
   }
 };