Add "panel_fitting" GPU feature type and use it for mirror mode.

chrome/browser/resources/gpu_internals/info_view.js

 // Copyright (c) 2012 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.
 
 
 /**
  * @fileoverview This view displays information on the current GPU
  * hardware.  Its primary usefulness is to allow users to copy-paste
  * their data in an easy to read format for bug reports.
  */
@@ skipping 65 matching lines @@
       var featureLabelMap = {
         '2d_canvas': 'Canvas',
         '3d_css': '3D CSS',
         'css_animation': 'CSS Animation',
         'compositing': 'Compositing',
         'webgl': 'WebGL',
         'multisampling': 'WebGL multisampling',
         'flash_3d': 'Flash 3D',
         'flash_stage3d': 'Flash Stage3D',
         'texture_sharing': 'Texture Sharing',
-        'video_decode': 'Video Decode'
+        'video_decode': 'Video Decode',
+        'panel_fitting': 'Panel Fitting'
       };
       var statusLabelMap = {
         'disabled_software': 'Software only. Hardware acceleration disabled.',
         'disabled_software_animated': 'Software animated.',
         'disabled_off': 'Unavailable. Hardware acceleration disabled.',
         'software': 'Software rendered. Hardware acceleration not enabled.',
         'unavailable_off': 'Unavailable. Hardware acceleration unavailable',
         'unavailable_software':
             'Software only, hardware acceleration unavailable',
         'enabled_readback': 'Hardware accelerated, but at reduced performance',
@@ skipping 188 matching lines @@
 
       peg.innerHTML = '';
       peg.appendChild(template);
     }
   };
 
   return {
     InfoView: InfoView
   };
 });