Use the default theme as the fallback UI in Blink

webkit/glue/webkitplatformsupport_impl.h

Index: webkit/glue/webkitplatformsupport_impl.h
diff --git a/webkit/glue/webkitplatformsupport_impl.h b/webkit/glue/webkitplatformsupport_impl.h
index 1c3a097b4251dd411d8d8109ca08d8bbbd7dae86..dc1bb97763926c2221c7cb7ead0c36003fafa26c 100644
--- a/webkit/glue/webkitplatformsupport_impl.h
+++ b/webkit/glue/webkitplatformsupport_impl.h
@@ -13,11 +13,10 @@
 #include "third_party/WebKit/Source/Platform/chromium/public/Platform.h"
 #include "ui/base/layout.h"
 #include "webkit/glue/resource_loader_bridge.h"
+#include "webkit/glue/webfallbackthemeengine_impl.h"
 #include "webkit/glue/webkit_glue_export.h"
 
-#if defined(USE_DEFAULT_RENDER_THEME)
-#include "webkit/glue/webthemeengine_impl_default.h"
-#elif defined(OS_WIN)
+#if defined(OS_WIN)
 #include "webkit/glue/webthemeengine_impl_win.h"
 #elif defined(OS_MACOSX)
 #include "webkit/glue/webthemeengine_impl_mac.h"
@@ -56,7 +55,10 @@ class WEBKIT_GLUE_EXPORT WebKitPlatformSupportImpl :
     const std::vector<float>& new_touchscreen);
 
   // Platform methods (partial implementation):
+#if !defined(USE_DEFAULT_RENDER_THEME)
   virtual WebKit::WebThemeEngine* themeEngine();
+#endif
+  virtual WebKit::WebFallbackThemeEngine* fallbackThemeEngine();
 
   virtual base::PlatformFile databaseOpenFile(
       const WebKit::WebString& vfs_file_name, int desired_flags);
@@ -191,7 +193,8 @@ class WEBKIT_GLUE_EXPORT WebKitPlatformSupportImpl :
   double shared_timer_fire_time_;
   bool shared_timer_fire_time_was_set_while_suspended_;
   int shared_timer_suspended_;  // counter
-  WebThemeEngineImpl theme_engine_;
+  WebThemeEngineImpl native_theme_engine_;
+  WebFallbackThemeEngineImpl fallback_theme_engine_;
   base::ThreadLocalStorage::Slot current_thread_slot_;
   scoped_ptr<webkit::WebCompositorSupportImpl> compositor_support_;
   scoped_ptr<FlingCurveConfiguration> fling_curve_configuration_;