Add a flag to allow renderer to use software compositor when GL compositor doesn't work.

chrome/browser/chromeos/login/chrome_restart_request.cc

 // Copyright 2013 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.
 
 #include "chrome/browser/chromeos/login/chrome_restart_request.h"
 
 #include <vector>
 
 #include "ash/ash_switches.h"
 #include "base/chromeos/chromeos_version.h"
@@ skipping 61 matching lines @@
       ::switches::kDeviceManagementUrl,
       ::switches::kDisableAccelerated2dCanvas,
       ::switches::kDisableAcceleratedOverflowScroll,
       ::switches::kDisableAcceleratedPlugins,
       ::switches::kDisableAcceleratedVideoDecode,
       ::switches::kDisableBrowserPluginCompositing,
       ::switches::kDisableDelegatedRenderer,
       ::switches::kDisableForceCompositingMode,
       ::switches::kDisableGpuShaderDiskCache,
       ::switches::kDisableGpuWatchdog,
+      ::switches::kDisableGpuCompositing,
       ::switches::kDisableLegacyEncryptedMedia,
       ::switches::kDisablePanelFitting,
       ::switches::kDisableSeccompFilterSandbox,
       ::switches::kDisableSetuidSandbox,
       ::switches::kDisableThreadedCompositing,
       ::switches::kDisableTouchDragDrop,
       ::switches::kDisableTouchEditing,
       ::switches::kDisableWebKitMediaSource,
       ::switches::kDisableAcceleratedFixedRootBackground,
       ::switches::kEnableAcceleratedFixedRootBackground,
@@ skipping 261 matching lines @@
     // Relaunch chrome without session manager on dev box.
     ReLaunch(command_line);
     return;
   }
 
   // ChromeRestartRequest deletes itself after request sent to session manager.
   (new ChromeRestartRequest(command_line))->Start();
 }
 
 }  // namespace chromeos