Revert of Deletes mojo::Callback

components/mus/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 COMPONENTS_MUS_WS_WINDOW_TREE_H_
 #define COMPONENTS_MUS_WS_WINDOW_TREE_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <memory>
 #include <queue>
 #include <set>
 #include <string>
 #include <vector>
 
-#include "base/callback.h"
 #include "base/containers/hash_tables.h"
 #include "base/macros.h"
 #include "cc/ipc/surface_id.mojom.h"
 #include "components/mus/public/interfaces/window_tree.mojom.h"
 #include "components/mus/ws/access_policy_delegate.h"
 #include "components/mus/ws/ids.h"
 #include "components/mus/ws/user_id.h"
 #include "components/mus/ws/window_tree_binding.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 
@@ skipping 310 matching lines @@
                           Id transient_window) override;
   void RemoveTransientWindowFromParent(uint32_t change_id,
                                        Id transient_window_id) override;
   void SetModal(uint32_t change_id, Id window_id) override;
   void ReorderWindow(uint32_t change_Id,
                      Id window_id,
                      Id relative_window_id,
                      mojom::OrderDirection direction) override;
   void GetWindowTree(
       Id window_id,
-      const base::Callback<void(mojo::Array<mojom::WindowDataPtr>)>& callback)
+      const mojo::Callback<void(mojo::Array<mojom::WindowDataPtr>)>& callback)
       override;
   void SetCapture(uint32_t change_id, Id window_id) override;
   void ReleaseCapture(uint32_t change_id, Id window_id) override;
   void SetEventObserver(mojom::EventMatcherPtr matcher,
                         uint32_t observer_id) override;
   void SetWindowBounds(uint32_t change_id,
                        Id window_id,
                        const gfx::Rect& bounds) override;
   void SetWindowVisibility(uint32_t change_id,
                            Id window_id,
@@ skipping 115 matching lines @@
   std::unique_ptr<WaitingForTopLevelWindowInfo>
       waiting_for_top_level_window_info_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTree);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_WINDOW_TREE_H_