Change name of NativeTheme::instance() to make it clear it's web only.

ui/views/view.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_VIEWS_VIEW_H_
 #define UI_VIEWS_VIEW_H_
 
 #include <algorithm>
 #include <map>
 #include <set>
@@ skipping 495 matching lines @@
 
   // The border object is owned by this object and may be NULL.
   virtual void SetBorder(scoped_ptr<Border> b);
   const Border* border() const { return border_.get(); }
   Border* border() { return border_.get(); }
 
   // Get the theme provider from the parent widget.
   ui::ThemeProvider* GetThemeProvider() const;
 
   // Returns the NativeTheme to use for this View. This calls through to
-  // GetNativeTheme() on the Widget this View is in. If this View is not in a
-  // Widget this returns ui::NativeTheme::instance().
+  // GetNativeTheme() on the Widget this View is in, or provides a default
+  // theme if there's no widget. Warning: the default theme might not be
+  // correct; you should probably override OnNativeThemeChanged().
   ui::NativeTheme* GetNativeTheme() {
     return const_cast<ui::NativeTheme*>(
         const_cast<const View*>(this)->GetNativeTheme());
   }
   const ui::NativeTheme* GetNativeTheme() const;
 
   // RTL painting --------------------------------------------------------------
 
   // This method determines whether the gfx::Canvas object passed to
   // View::Paint() needs to be transformed such that anything drawn on the
@@ skipping 1034 matching lines @@
   // Belongs to this view, but it's reference-counted on some platforms
   // so we can't use a scoped_ptr. It's dereferenced in the destructor.
   NativeViewAccessibility* native_view_accessibility_;
 
   DISALLOW_COPY_AND_ASSIGN(View);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_VIEW_H_