Set focusibility correctly when initializing a window in mus+ash.

ui/aura/mus/window_tree_client.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 UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 #define UI_AURA_MUS_WINDOW_TREE_CLIENT_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 378 matching lines @@
   void WmDisplayRemoved(int64_t display_id) override;
   void WmDisplayModified(const display::Display& display) override;
   void WmSetBounds(uint32_t change_id,
                    Id window_id,
                    const gfx::Rect& transit_bounds_in_pixels) override;
   void WmSetProperty(
       uint32_t change_id,
       Id window_id,
       const std::string& name,
       const base::Optional<std::vector<uint8_t>>& transit_data) override;
+  void WmSetCanFocus(Id window_id, bool can_focus) override;
   void WmCreateTopLevelWindow(
       uint32_t change_id,
       ClientSpecificId requesting_client_id,
       const std::unordered_map<std::string, std::vector<uint8_t>>&
           transport_properties) override;
   void WmClientJankinessChanged(ClientSpecificId client_id,
                                 bool janky) override;
   void WmPerformMoveLoop(uint32_t change_id,
                          Id window_id,
                          ui::mojom::MoveLoopSource source,
@@ skipping 132 matching lines @@
   std::unique_ptr<ui::Gpu> gpu_;
   std::unique_ptr<MusContextFactory> compositor_context_factory_;
   base::WeakPtrFactory<WindowTreeClient> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeClient);
 };
 
 }  // namespace aura
 
 #endif  // UI_AURA_MUS_WINDOW_TREE_CLIENT_H_