DevTools: Remember the last focused widget.

third_party/WebKit/Source/devtools/front_end/layers/LayersPanel.js

 /*
  * Copyright (C) 2013 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 55 matching lines @@
 
 WebInspector.LayersPanel.DetailsViewTabs = {
     Details: "details",
     Profiler: "profiler"
 };
 
 WebInspector.LayersPanel.prototype = {
     focus: function()
     {
         this._layerTreeOutline.focus();
+        this.wasFocused();
     },
 
     wasShown: function()
     {
         WebInspector.Panel.prototype.wasShown.call(this);
         if (this._model)
             this._model.enable();
         this._layerTreeOutline.focus();
     },
 
@@ skipping 91 matching lines @@
     reveal: function(snapshotData)
     {
         if (!(snapshotData instanceof WebInspector.DeferredLayerTree))
             return Promise.reject(new Error("Internal error: not a WebInspector.DeferredLayerTree"));
         var panel = /** @type {!WebInspector.LayersPanel} */ (self.runtime.sharedInstance(WebInspector.LayersPanel));
         WebInspector.inspectorView.setCurrentPanel(panel);
         panel._showLayerTree(/** @type {!WebInspector.DeferredLayerTree} */ (snapshotData));
         return Promise.resolve();
     }
 }