aura-mus: Implement Deactivate().

ui/aura/mus/window_tree_client.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 "ui/aura/mus/window_tree_client.h"
 
 #include <stddef.h>
 
 #include <string>
 #include <utility>
@@ skipping 1562 matching lines @@
   base::Optional<gfx::Rect> out_rect = base::nullopt;
   if (mask_rect) {
     out_rect = gfx::ConvertRectToPixel(ScaleFactorForDisplay(window),
                                        mask_rect.value());
   }
 
   tree_->SetHitTestMask(WindowMus::Get(window_tree_host->window())->server_id(),
                         out_rect);
 }
 
+void WindowTreeClient::OnWindowTreeHostClearFocus() {
+  focus_synchronizer_->ClearFocus();
+}
+
 std::unique_ptr<WindowPortMus> WindowTreeClient::CreateWindowPortForTopLevel(
     const std::map<std::string, std::vector<uint8_t>>* properties) {
   std::unique_ptr<WindowPortMus> window_port =
       base::MakeUnique<WindowPortMus>(this, WindowMusType::TOP_LEVEL);
   roots_.insert(window_port.get());
 
   window_port->set_server_id(MakeTransportId(client_id_, next_window_id_++));
   RegisterWindowMus(window_port.get());
 
   std::unordered_map<std::string, std::vector<uint8_t>> transport_properties;
@@ skipping 94 matching lines @@
   return ScheduleInFlightChange(base::MakeUnique<InFlightCaptureChange>(
       this, capture_synchronizer_.get(), window));
 }
 
 uint32_t WindowTreeClient::CreateChangeIdForFocus(WindowMus* window) {
   return ScheduleInFlightChange(base::MakeUnique<InFlightFocusChange>(
       this, focus_synchronizer_.get(), window));
 }
 
 }  // namespace aura