Enable HTML5 lexer by default.

webkit/glue/webpreferences.h

 // Copyright (c) 2006-2008 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, common/render_messages.h, and
 // browser/profile.cc.
 
@@ skipping 91 matching lines @@
         databases_enabled(false),
         application_cache_enabled(false),
         tabs_to_links(true),
         user_style_sheet_enabled(false),
         author_and_user_styles_enabled(true),
         allow_universal_access_from_file_urls(false),
         allow_file_access_from_file_urls(false),
         experimental_webgl_enabled(false),
         show_composited_layer_borders(false),
         accelerated_compositing_enabled(false),
-        enable_html5_parser(false) {
+        enable_html5_parser(true) {
   }
 
   void Apply(WebKit::WebView* web_view) const;
 };
 
 #endif  // WEBKIT_GLUE_WEBPREFERENCES_H__