Adds View::GetNativeTheme() to get the NativeTheme. The interesting

ui/views/widget/widget.h

Index: ui/views/widget/widget.h
diff --git a/ui/views/widget/widget.h b/ui/views/widget/widget.h
index e906327fe3e692d6b958d7ab939106c1712373bb..3c382eb08f48c98d55a320c7b65421aedab7f2e1 100644
--- a/ui/views/widget/widget.h
+++ b/ui/views/widget/widget.h
@@ -45,6 +45,7 @@ namespace ui {
 class Accelerator;
 class Compositor;
 class Layer;
+class NativeTheme;
 class OSExchangeData;
 class ThemeProvider;
 }
@@ -431,6 +432,8 @@ class VIEWS_EXPORT Widget : public internal::NativeWidgetDelegate,
   // Returns the ThemeProvider that provides theme resources for this Widget.
   virtual ui::ThemeProvider* GetThemeProvider() const;
 
+  ui::NativeTheme* GetNativeTheme();
+
   // Returns the FocusManager for this widget.
   // Note that all widgets in a widget hierarchy share the same focus manager.
   FocusManager* GetFocusManager();