Aura desktop: Fix tab dragging within a single chrome window.

ui/base/x/x11_util.h

Index: ui/base/x/x11_util.h
diff --git a/ui/base/x/x11_util.h b/ui/base/x/x11_util.h
index a0ac39876db50e6801799a861ae8f8948db2813c..f0ee270761d572fbc70d018aa880d9fc2733f8df 100644
--- a/ui/base/x/x11_util.h
+++ b/ui/base/x/x11_util.h
@@ -188,6 +188,9 @@ class EnumerateWindowsDelegate {
 UI_EXPORT bool EnumerateAllWindows(EnumerateWindowsDelegate* delegate,
                                    int max_depth);
 
+// Enumerates the top-level windows of the current display.
+UI_EXPORT void EnumerateTopLevelWindows(ui::EnumerateWindowsDelegate* delegate);
+
 // Returns all children windows of a given window in top-to-bottom stacking
 // order.
 UI_EXPORT bool GetXWindowStack(XID window, std::vector<XID>* windows);