Add ContextMenuSourceType to views::ContextMenuController::ShowContextMenuForView.

ash/desktop_background/desktop_background_view.h

Index: ash/desktop_background/desktop_background_view.h
diff --git a/ash/desktop_background/desktop_background_view.h b/ash/desktop_background/desktop_background_view.h
index 8528e7714d6a1abe9b880f3f9d2376a25e9a7dc0..dbd33206fb2cf5fb9b92e97a92788cc9b4b9f6d7 100644
--- a/ash/desktop_background/desktop_background_view.h
+++ b/ash/desktop_background/desktop_background_view.h
@@ -25,7 +25,8 @@ class DesktopBackgroundView : public views::View,
 
   // Overridden from views::ContextMenuController:
   virtual void ShowContextMenuForView(views::View* source,
-                                      const gfx::Point& point) OVERRIDE;
+                                      const gfx::Point& point,
+                                      ui::MenuSourceType source_type) OVERRIDE;
 
   DISALLOW_COPY_AND_ASSIGN(DesktopBackgroundView);
 };