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

ui/views/view.cc

Index: ui/views/view.cc
diff --git a/ui/views/view.cc b/ui/views/view.cc
index 46bb7be9d230e22aa84dff30ff9952cc16e9fbdf..3bced000cacbef07e9ea2d699a7929676ab7887e 100644
--- a/ui/views/view.cc
+++ b/ui/views/view.cc
@@ -840,12 +840,12 @@ const ui::NativeTheme* View::GetNativeTheme() const {
     return widget->GetNativeTheme();
 
 #if defined(OS_WIN)
-  // On Windows, ui::NativeTheme::instance() returns NativeThemeWinAura because
-  // that's what the renderer wants, but Views should default to NativeThemeWin.
-  // TODO(estade): clean this up, see http://crbug.com/558029
+  // On Windows, ui::NativeTheme::GetInstanceForWeb() returns NativeThemeWinAura
+  // because that's what the renderer wants, but Views should default to
+  // NativeThemeWin. TODO(estade): clean this up, see http://crbug.com/558029
   return ui::NativeThemeWin::instance();
 #else
-  return ui::NativeTheme::instance();
+  return ui::NativeTheme::GetInstanceForWeb();
 #endif
 }