Remove frame flattening setting from Chromium.

webkit/glue/webpreferences.h

 // 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.
 //
 // A struct for managing webkit's settings.
 //
 // Adding new values to this class probably involves updating
 // WebKit::WebSettings, content/common/view_messages.h, browser/tab_contents/
 // render_view_host_delegate_helper.cc, and browser/profiles/profile.cc.
 
@@ skipping 73 matching lines @@
   bool local_storage_enabled;
   bool databases_enabled;
   bool application_cache_enabled;
   bool tabs_to_links;
   bool caret_browsing_enabled;
   bool hyperlink_auditing_enabled;
   bool is_online;
   bool user_style_sheet_enabled;
   GURL user_style_sheet_location;
   bool author_and_user_styles_enabled;
-  bool frame_flattening_enabled;
   bool allow_universal_access_from_file_urls;
   bool allow_file_access_from_file_urls;
   bool webaudio_enabled;
   bool experimental_webgl_enabled;
   bool flash_3d_enabled;
   bool flash_stage3d_enabled;
   bool flash_stage3d_baseline_enabled;
   bool gl_multisampling_enabled;
   bool privileged_webgl_extensions_enabled;
   bool webgl_errors_to_console_enabled;
@@ skipping 66 matching lines @@
   // the embedder to use the same default value.
   WebPreferences();
   ~WebPreferences();
 
   void Apply(WebKit::WebView* web_view) const;
 };
 
 }  // namespace webkit_glue
 
 #endif  // WEBKIT_GLUE_WEBPREFERENCES_H__