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

services/ui/ws/window_tree.h

 // 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.
 
 #ifndef SERVICES_UI_WS_WINDOW_TREE_H_
 #define SERVICES_UI_WS_WINDOW_TREE_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 466 matching lines @@
                                  Id transport_window_id) override;
   void OnAcceleratorAck(uint32_t event_id, mojom::EventResult result) override;
 
   // AccessPolicyDelegate:
   bool HasRootForAccessPolicy(const ServerWindow* window) const override;
   bool IsWindowKnownForAccessPolicy(const ServerWindow* window) const override;
   bool IsWindowRootOfAnotherTreeForAccessPolicy(
       const ServerWindow* window) const override;
 
   // DragSource:
-  void OnDragCompleted(bool success) override;
+  void OnDragCompleted(bool success, uint32_t action_taken) override;
   ServerWindow* GetWindowById(const WindowId& id) override;
   DragTargetConnection* GetDragTargetForWindow(
       const ServerWindow* window) override;
 
   // DragTargetConnection:
   void PerformOnDragDropStart(
       mojo::Map<mojo::String, mojo::Array<uint8_t>> mime_data) override;
   void PerformOnDragEnter(
       const ServerWindow* window,
       uint32_t event_flags,
@@ skipping 69 matching lines @@
       waiting_for_top_level_window_info_;
   bool embedder_intercepts_events_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTree);
 };
 
 }  // namespace ws
 }  // namespace ui
 
 #endif  // SERVICES_UI_WS_WINDOW_TREE_H_