DevTools: make responsive design a master switch for emulation.

Source/devtools/front_end/ui/TabbedPane.js

 /*
  * Copyright (C) 2010 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 1129 matching lines @@
     },
 
     /**
      * @param {string} id
      * @param {string} title
      * @param {!WebInspector.Setting} setting
      */
     _toggleSettingBasedView: function(id, title, setting)
     {
         this._tabbedPane.closeTab(id);
-        if (setting.get())
+        if (setting.get()) {
             this._tabbedPane.appendTab(id, title, new WebInspector.View());
+            this._tabbedPane.selectTab(id);
+        }
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _tabSelected: function(event)
     {
         var tabId = this._tabbedPane.selectedTabId;
         if (!tabId)
             return;
         var view = this._viewForId(tabId);
         if (view)
             this._tabbedPane.changeTabView(tabId, view);
     },
 
     /**
      * @return {?WebInspector.View}
      */
     _viewForId: function(id)
     {
         if (this._views.contains(id))
             return /** @type {!WebInspector.View} */ (this._views.get(id));
         var view = this._extensions[id] ? /** @type {!WebInspector.View} */ (this._extensions[id].instance()) : null;
         this._views.put(id, view);
         if (this._viewCallback && view)
             this._viewCallback(id, view);
         return view;
     }
 }