Mac: ExternalPopupMenu::close should hide a showing popup menu.

content/port/browser/render_view_host_delegate_view.h

Index: content/port/browser/render_view_host_delegate_view.h
diff --git a/content/port/browser/render_view_host_delegate_view.h b/content/port/browser/render_view_host_delegate_view.h
index 4991926c1457b57414255062559ef8cf9ac6a591..0d6cef7892c7a99eec6e3a53148ef83d7e3f2d84 100644
--- a/content/port/browser/render_view_host_delegate_view.h
+++ b/content/port/browser/render_view_host_delegate_view.h
@@ -47,6 +47,9 @@ class CONTENT_EXPORT RenderViewHostDelegateView {
                              bool right_aligned,
                              bool allow_multiple_selection) = 0;
 
+  // Hides a popup menu opened by ShowPopupMenu().
+  virtual void HidePopupMenu() = 0;
+
   // The user started dragging content of the specified type within the
   // RenderView. Contextual information about the dragged content is supplied
   // by DropData. If the delegate's view cannot start the drag for /any/