Avoid copying the CachedUAStyle when possible

Source/core/rendering/style/CachedUAStyle.h

  /*
  * Copyright (C) 2013 Google, Inc.
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  *
  * 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.
  *
@@ skipping 21 matching lines @@
 // applyMatchedProperties for later use during adjustRenderStyle.
 class CachedUAStyle {
 public:
     CachedUAStyle()
         : hasAppearance(false)
         , backgroundLayers(BackgroundFillLayer)
         , backgroundColor(StyleColor::currentColor())
     { }
 
     explicit CachedUAStyle(const RenderStyle* style)
-        : hasAppearance(style->hasAppearance())
+        : hasAppearance(true)
         , backgroundLayers(BackgroundFillLayer)
         , backgroundColor(StyleColor::currentColor())
     {
-        // RenderTheme::adjustStyle is the only consumer of this data.
-        // It only cares about the styles if appearance is set,
-        // so we cheat and don't bother to copy them when !hasAppearance.
-        if (!hasAppearance)
-            return;
+        ASSERT(style->hasAppearance());
         border = style->border();
         backgroundLayers = *style->backgroundLayers();
         backgroundColor = style->backgroundColor();
     }
 
     bool hasAppearance;
     BorderData border;
     FillLayer backgroundLayers;
     StyleColor backgroundColor;
 };
 
 
 } // namespace WebCore
 
 #endif // CachedUAStyle_h