DevTools: bring back existing panel selection rendering (border image)

Source/devtools/devtools.gypi

 #
 # 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 751 matching lines @@
             'front_end/Images/toolbarButtonGlyphs.png',
             'front_end/Images/toolbarButtonGlyphs_2x.png',
             'front_end/Images/toolbarResizerHorizontal.png',
             'front_end/Images/toolbarResizerVertical.png',
             'front_end/Images/thumbActiveHoriz.png',
             'front_end/Images/thumbActiveVert.png',
             'front_end/Images/thumbHoriz.png',
             'front_end/Images/thumbHoverHoriz.png',
             'front_end/Images/thumbHoverVert.png',
             'front_end/Images/thumbVert.png',
+            'front_end/Images/toolbarItemSelected.png',
             'front_end/Images/touchCursor.png',
             'front_end/Images/touchCursor_2x.png',
             'front_end/Images/updateServiceWorker.svg',
         ],
         'devtools_extension_api_files': [
             'front_end/extensions/ExtensionAPI.js',
         ],
     },
 }