MacViews: Attach child windows when parent is on the screen.

ui/views/cocoa/views_nswindow_delegate.h

Index: ui/views/cocoa/views_nswindow_delegate.h
diff --git a/ui/views/cocoa/views_nswindow_delegate.h b/ui/views/cocoa/views_nswindow_delegate.h
index 7dc64b662366a1cd4dafa54627f7bcc339e2f133..2d93568950095c90405d488962c2de478f4bedd9 100644
--- a/ui/views/cocoa/views_nswindow_delegate.h
+++ b/ui/views/cocoa/views_nswindow_delegate.h
@@ -35,10 +35,6 @@ VIEWS_EXPORT
 // Initialize with the given |parent|.
 - (id)initWithBridgedNativeWidget:(views::BridgedNativeWidget*)parent;
 
-// Notify that the window is about to be reordered on screen. This ensures a
-// paint will occur, even if Cocoa has not yet updated the window visibility.
-- (void)onWindowOrderWillChange:(NSWindowOrderingMode)orderingMode;
-
 // Notify that the window has been reordered in (or removed from) the window
 // server's screen list. This is a substitute for -[NSWindowDelegate
 // windowDidExpose:], which is only sent for nonretained windows (those without