Add option --dump-render-tree to content_shell to dump the render tree as text.

content/content_shell.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'content_shell_lib',
       'type': 'static_library',
       'defines!': ['CONTENT_IMPLEMENTATION'],
@@ skipping 51 matching lines @@
         'shell/shell_content_renderer_client.cc',
         'shell/shell_content_renderer_client.h',
         'shell/shell_content_utility_client.cc',
         'shell/shell_content_utility_client.h',
         'shell/shell_devtools_delegate.cc',
         'shell/shell_devtools_delegate.h',
         'shell/shell_download_manager_delegate.cc',
         'shell/shell_download_manager_delegate.h',
         'shell/shell_main_delegate.cc',
         'shell/shell_main_delegate.h',
+        'shell/shell_messages.cc',
+        'shell/shell_messages.h',
+        'shell/shell_render_view_host_observer.cc',
+        'shell/shell_render_view_host_observer.h',
         'shell/shell_render_view_observer.cc',
         'shell/shell_render_view_observer.h',
         'shell/shell_resource_context.cc',
         'shell/shell_resource_context.h',
+        'shell/shell_switches.cc',
+        'shell/shell_switches.h',
         'shell/shell_url_request_context_getter.cc',
         'shell/shell_url_request_context_getter.h',
       ],
       'msvs_settings': {
         'VCLinkerTool': {
           'SubSystem': '2',  # Set /SUBSYSTEM:WINDOWS
         },
       },
       'conditions': [
         ['OS=="win" and win_use_allocator_shim==1', {
@@ skipping 140 matching lines @@
         }],
         ['toolkit_uses_gtk == 1', {
           'dependencies': [
             '<(DEPTH)/build/linux/system.gyp:gtk',
           ],
         }],
       ],
     },
   ],
 }