aura-mus: Implement Deactivate().

ui/aura/mus/window_tree_host_mus.cc

 // Copyright 2015 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_host_mus.h"
 
 #include "base/memory/ptr_util.h"
 #include "ui/aura/env.h"
 #include "ui/aura/mus/input_method_mus.h"
 #include "ui/aura/mus/window_port_mus.h"
@@ skipping 99 matching lines @@
 
 void WindowTreeHostMus::SetClientArea(const gfx::Insets& insets) {
   delegate_->OnWindowTreeHostClientAreaWillChange(this, insets,
                                                   std::vector<gfx::Rect>());
 }
 
 void WindowTreeHostMus::SetHitTestMask(const base::Optional<gfx::Rect>& rect) {
   delegate_->OnWindowTreeHostHitTestMaskWillChange(this, rect);
 }
 
+void WindowTreeHostMus::ClearFocus() {
+  delegate_->OnWindowTreeHostClearFocus();
+}

[Elliot Glaysher, 2016/12/13 23:30:20]

I don't like this emerging pattern. DesktopWindowTreeHostMus calls this method
through its base class which calls WindowTreeClient through a delegate
interface. Seems like a lot of forwarding for a simple thing.

+
 display::Display WindowTreeHostMus::GetDisplay() const {
   for (const display::Display& display :
        display::Screen::GetScreen()->GetAllDisplays()) {
     if (display.id() == display_id_)
       return display;
   }
   return display::Display();
 }
 
 void WindowTreeHostMus::ShowImpl() {
@@ skipping 31 matching lines @@
 void WindowTreeHostMus::OnCloseRequest() {
   OnHostCloseRequested();
 }
 
 gfx::ICCProfile WindowTreeHostMus::GetICCProfileForCurrentDisplay() {
   // TODO: This should read the profile from mus. crbug.com/647510
   return gfx::ICCProfile();
 }
 
 }  // namespace aura