mus drag and drop: return the completed effect to the caller.

services/ui/ws/window_tree.cc

Index: services/ui/ws/window_tree.cc
diff --git a/services/ui/ws/window_tree.cc b/services/ui/ws/window_tree.cc
index dad121fdd3271b407c845a26dcf465f18ab2227f..23b7167096f7ae683a3ceecc0612317d6933b02a 100644
--- a/services/ui/ws/window_tree.cc
+++ b/services/ui/ws/window_tree.cc
@@ -1778,7 +1778,7 @@ bool WindowTree::IsWindowRootOfAnotherTreeForAccessPolicy(
   return tree && tree != this;
 }
 
-void WindowTree::OnDragCompleted(bool success) {
+void WindowTree::OnDragCompleted(bool success, uint32_t action_taken) {
   DCHECK(window_server_->in_drag_loop());
 
   if (window_server_->GetCurrentDragLoopInitiator() != this)
@@ -1794,6 +1794,7 @@ void WindowTree::OnDragCompleted(bool success) {
   WindowManagerState* wms = display_root->window_manager_state();
   wms->EndDragDrop();
 
+  client()->OnDragCompletedReturnValue(change_id, action_taken);

[sky, 2016/09/20 21:42:03]

Can we only call OnDragCompletedReturnValue? By that I mean can you remove the
call to OnChangeCompleted on the next line?

[Elliot Glaysher, 2016/09/20 22:05:25]

Removed OnChangeCompleted and made OnDragCompletedReturnValue take success. It
implicitly calls OnChangeCompleted on the other side.

   client()->OnChangeCompleted(change_id, success);
 }