[DevTools] Rework some focus code.

third_party/WebKit/Source/devtools/front_end/ui/SwatchPopoverHelper.js

 // Copyright 2016 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.SwatchPopoverHelper = function()
 {
@@ skipping 49 matching lines @@
         this.reposition();
 
         var document = this._popover.element.ownerDocument;
         document.addEventListener("mousedown", this._hideProxy, false);
         document.defaultView.addEventListener("resize", this._hideProxy, false);
         this._view.contentElement.addEventListener("keydown", this._boundOnKeyDown, false);
     },
 
     reposition: function()
     {
-        if (!this._previousFocusElement)
-            this._previousFocusElement = WebInspector.currentFocusElement();
         // Unbind "blur" listener to avoid reenterability: |popover.showView| will hide the popover and trigger it synchronously.
         this._view.contentElement.removeEventListener("focusout", this._boundFocusOut, false);
         this._popover.showView(this._view, this._anchorElement);
         this._view.contentElement.addEventListener("focusout", this._boundFocusOut, false);
-        WebInspector.setCurrentFocusElement(this._view.contentElement);
+        if (!this._focusRestorer)
+            this._focusRestorer = new WebInspector.WidgetFocusRestorer(this._view);
     },
 
     /**
      * @param {boolean=} commitEdit
      */
     hide: function(commitEdit)
     {
         if (this._isHidden)
             return;
         var document = this._popover.element.ownerDocument;
         this._isHidden = true;
         this._popover.hide();
 
         document.removeEventListener("mousedown", this._hideProxy, false);
         document.defaultView.removeEventListener("resize", this._hideProxy, false);
 
         if (this._hiddenCallback)
             this._hiddenCallback.call(null, !!commitEdit);
 
-        WebInspector.setCurrentFocusElement(this._previousFocusElement);
-        delete this._previousFocusElement;
+        this._focusRestorer.restore();
         delete this._anchorElement;
         if (this._view) {
             this._view.detach();
             this._view.contentElement.removeEventListener("keydown", this._boundOnKeyDown, false);
             this._view.contentElement.removeEventListener("focusout", this._boundFocusOut, false);
             delete this._view;
         }
     },
 
     /**
      * @param {!Event} event
      */
     _onKeyDown: function(event)
     {
         if (event.key === "Enter") {
             this.hide(true);
             event.consume(true);
             return;
         }
         if (event.key === "Escape") {
             this.hide(false);
             event.consume(true);
         }
     },
 
     __proto__: WebInspector.Object.prototype
 }