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

services/ui/ws/window_tree.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "services/ui/ws/window_tree.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1760 matching lines @@
     const ServerWindow* window) const {
   return IsWindowKnown(window);
 }
 
 bool WindowTree::IsWindowRootOfAnotherTreeForAccessPolicy(
     const ServerWindow* window) const {
   WindowTree* tree = window_server_->GetTreeWithRoot(window);
   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)
     return;
 
   uint32_t change_id = window_server_->GetCurrentDragLoopChangeId();
   ServerWindow* window = window_server_->GetCurrentDragLoopWindow();
   WindowManagerDisplayRoot* display_root = GetWindowManagerDisplayRoot(window);
   if (!display_root)
     return;
 
   window_server_->EndDragLoop();
   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);
 }
 
 ServerWindow* WindowTree::GetWindowById(const WindowId& id) {
   return GetWindow(id);
 }
 
 DragTargetConnection* WindowTree::GetDragTargetForWindow(
     const ServerWindow* window) {
   if (!window)
@@ skipping 65 matching lines @@
   client()->OnCompleteDrop(client_window_id.id, event_flags, cursor_offset,
                            effect_bitmask, callback);
 }
 
 void WindowTree::PerformOnDragDropDone() {
   client()->OnDragDropDone();
 }
 
 }  // namespace ws
 }  // namespace ui