Switch to LayoutThemeMobile when emulating mobile device in DevTools.

third_party/WebKit/Source/core/layout/LayoutTheme.h

 /*
  * This file is part of the theme implementation for form controls in WebCore.
  *
  * Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010, 2012 Apple Computer, 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.
  *
@@ skipping 30 matching lines @@
 class Theme;
 class ThemePainter;
 
 class CORE_EXPORT LayoutTheme : public RefCounted<LayoutTheme> {
 protected:
     LayoutTheme();
 
 public:
     virtual ~LayoutTheme() { }
 
-    // This function is to be implemented in your platform-specific theme implementation to hand back the
-    // appropriate platform theme.
     static LayoutTheme& theme();
 
     virtual ThemePainter& painter() = 0;
 
     static void setSizeIfAuto(ComputedStyle&, const IntSize&);
 
     // This method is called whenever style has been computed for an element and the appearance
     // property has been set to a value other than "none".  The theme should map in all of the appropriate
     // metrics and defaults given the contents of the style.  This includes sophisticated operations like
     // selection of control size based off the font, the disabling of appearance when certain other properties like
@@ skipping 170 matching lines @@
     static bool isIndeterminate(const LayoutObject&);
     static bool isEnabled(const LayoutObject&);
     static bool isFocused(const LayoutObject&);
     static bool isPressed(const LayoutObject&);
     static bool isSpinUpButtonPartPressed(const LayoutObject&);
     static bool isHovered(const LayoutObject&);
     static bool isSpinUpButtonPartHovered(const LayoutObject&);
     static bool isReadOnlyControl(const LayoutObject&);
 
 private:
+    // This function is to be implemented in your platform-specific theme implementation to hand back the
+    // appropriate platform theme.
+    static LayoutTheme& nativeTheme();
+
     Color m_customFocusRingColor;
     bool m_hasCustomFocusRingColor;
 
     // This color is expected to be drawn on a semi-transparent overlay,
     // making it more transparent than its alpha value indicates.
     static const RGBA32 defaultTapHighlightColor = 0x66000000;
 
     static const RGBA32 defaultCompositionBackgroundColor = 0xFFFFDD55;
 
 #if USE(NEW_THEME)
     Theme* m_platformTheme; // The platform-specific theme.
 #endif
 };
 
 } // namespace blink
 
 #endif // LayoutTheme_h