Use fallback in LayoutThemeMobile on mac.

third_party/WebKit/Source/core/layout/LayoutThemeMobile.cpp

 /*
  * Copyright (C) 2011 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 58 matching lines @@
     if (LayoutTestSupport::isRunningLayoutTest()) {
         // Match Linux spin button style in layout tests.
         // FIXME: Consider removing the conditional if a future Android theme matches this.
         IntSize size = Platform::current()->themeEngine()->getSize(WebThemeEngine::PartInnerSpinButton);
 
         style.setWidth(Length(size.width(), Fixed));
         style.setMinWidth(Length(size.width(), Fixed));
     }
 }
 
+bool LayoutThemeMobile::shouldUseFallbackTheme(const ComputedStyle& style) const
+{
+#if OS(MACOSX)
+    // Mac WebThemeEngine cannot handle these controls.
+    ControlPart part = style.appearance();
+    if (part == CheckboxPart || part == RadioPart)
+        return true;
+#endif
+    return LayoutThemeDefault::shouldUseFallbackTheme(style);
+}
+
 } // namespace blink