Get rid of user-level styles.

chrome/renderer/extensions/dispatcher.cc

 // 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.
 
 #include "chrome/renderer/extensions/dispatcher.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "base/debug/alias.h"
 #include "base/json/json_reader.h"
@@ skipping 1256 matching lines @@
     // insert the default platform app stylesheet into all documents that are
     // loaded in each app.
     std::string stylesheet =
         ResourceBundle::GetSharedInstance().
             GetRawDataResource(IDR_PLATFORM_APP_CSS).as_string();
     ReplaceFirstSubstringAfterOffset(&stylesheet, 0,
                                      "$FONTFAMILY", system_font_family_);
     ReplaceFirstSubstringAfterOffset(&stylesheet, 0,
                                      "$FONTSIZE", system_font_size_);
     frame->document().insertUserStyleSheet(
-        WebString::fromUTF8(stylesheet), WebDocument::UserStyleUserLevel);
+        WebString::fromUTF8(stylesheet), WebDocument::UserStyleAuthorLevel);
   }
 
   content_watcher_->DidCreateDocumentElement(frame);
 }
 
 void Dispatcher::DidMatchCSS(
     blink::WebFrame* frame,
     const blink::WebVector<blink::WebString>& newly_matching_selectors,
     const blink::WebVector<blink::WebString>& stopped_matching_selectors) {
   content_watcher_->DidMatchCSS(
@@ skipping 344 matching lines @@
     RenderView* background_view =
         ExtensionHelper::GetBackgroundPage(extension_id);
     if (background_view) {
       background_view->Send(new ExtensionHostMsg_EventAck(
           background_view->GetRoutingID()));
     }
   }
 }
 
 }  // namespace extensions