Avoids releasing capture in EndMoveLoop if capture was switched to another window while dragging

ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h

Index: ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
diff --git a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
index e369718838ce95eb0b1c39d210465470c93bd343..2843d5c5557465a2d20a2c228d12da3edb8b25a4 100644
--- a/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
+++ b/ui/views/widget/desktop_aura/desktop_window_tree_host_x11.h
@@ -50,6 +50,9 @@ class VIEWS_EXPORT DesktopWindowTreeHostX11
   // A way of converting an X11 |xid| host window into this object.
   static DesktopWindowTreeHostX11* GetHostForXID(XID xid);
 
+  // Returns if any DesktopWindowTreeHostX11 instance has capture.
+  static bool AnyHostHasCapture();
+
   // Get all open top-level windows. This includes windows that may not be
   // visible. This list is sorted in their stacking order, i.e. the first window
   // is the topmost window.