[DevTools] Rework some focus code.

third_party/WebKit/Source/devtools/front_end/components/DockController.js

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 96 matching lines @@
     /**
      * @return {boolean}
      */
     isVertical: function()
     {
         return this._dockSide === WebInspector.DockController.State.DockedToRight;
     },
 
     /**
      * @param {string} dockSide
+     * @suppressGlobalPropertiesCheck
      */
     setDockSide: function(dockSide)
     {
         if (this._states.indexOf(dockSide) === -1)
             dockSide = this._states[0];
 
         if (this._dockSide === dockSide)
             return;
 
         if (this._dockSide)
             this._lastDockStateSetting.set(this._dockSide);
 
-        WebInspector.DockController._previousFocusedElement = WebInspector.currentFocusElement();
+        this._savedFocus = document.deepActiveElement();
         var eventData = { from: this._dockSide, to: dockSide };
         this.dispatchEventToListeners(WebInspector.DockController.Events.BeforeDockSideChanged, eventData);
         console.timeStamp("DockController.setIsDocked");
         this._dockSide = dockSide;
         this._currentDockStateSetting.set(dockSide);
         InspectorFrontendHost.setIsDocked(dockSide !== WebInspector.DockController.State.Undocked, this._setIsDockedResponse.bind(this, eventData));
         this._updateUI();
         this.dispatchEventToListeners(WebInspector.DockController.Events.DockSideChanged, eventData);
     },
 
     /**
      * @param {{from: string, to: string}} eventData
      */
     _setIsDockedResponse: function(eventData)
     {
         this.dispatchEventToListeners(WebInspector.DockController.Events.AfterDockSideChanged, eventData);
-
-        if (WebInspector.DockController._previousFocusedElement)
-            WebInspector.DockController._previousFocusedElement.focus();
-        delete WebInspector.DockController._previousFocusedElement;
+        if (this._savedFocus) {
+            this._savedFocus.focus();
+            this._savedFocus = null;
+        }
     },
 
     /**
      * @suppressGlobalPropertiesCheck
      */
     _updateUI: function()
     {
         var body = document.body;  // Only for main window.
         switch (this._dockSide) {
         case WebInspector.DockController.State.DockedToBottom:
@@ skipping 65 matching lines @@
     item: function()
     {
         return WebInspector.dockController._closeButton;
     }
 }
 
 /**
  * @type {!WebInspector.DockController}
  */
 WebInspector.dockController;