OSX: Media appearance values don't support native focus ring.

third_party/WebKit/Source/core/layout/LayoutThemeMac.mm

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Google, Inc.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 1059 matching lines @@
 
 String LayoutThemeMac::extraDefaultStyleSheet()
 {
     return LayoutTheme::extraDefaultStyleSheet() +
         loadResourceAsASCIIString("themeInputMultipleFields.css") +
         loadResourceAsASCIIString("themeMac.css");
 }
 
 bool LayoutThemeMac::themeDrawsFocusRing(const ComputedStyle& style) const
 {
-    return (style.hasAppearance() && style.appearance() != TextFieldPart && style.appearance() != SearchFieldPart && style.appearance() != TextAreaPart && style.appearance() != MenulistButtonPart && style.appearance() != ListboxPart && !shouldUseFallbackTheme(style));
+    if (shouldUseFallbackTheme(style))
+        return false;
+    switch (style.appearance()) {
+    case CheckboxPart:
+    case RadioPart:
+    case PushButtonPart:
+    case SquareButtonPart:
+    case ButtonPart:
+    case MenulistPart:
+    case SliderThumbHorizontalPart:
+    case SliderThumbVerticalPart:
+        return true;
+
+    // Actually, they don't support native focus rings, but this function
+    // returns true for them in order to prevent Blink from drawing focus rings.
+    // SliderThumb*Part have focus rings, and we don't need to draw two focus
+    // rings for single slider.
+    case SliderHorizontalPart:
+    case SliderVerticalPart:
+        return true;
+
+    default:
+        return false;
+    }
 }
 
 bool LayoutThemeMac::shouldUseFallbackTheme(const ComputedStyle& style) const
 {
     ControlPart part = style.appearance();
     if (part == CheckboxPart || part == RadioPart)
         return style.effectiveZoom() != 1;
     return false;
 }
 
 } // namespace blink