Hook up proper FocusController for simple_wm.

ui/views/window/custom_frame_view.h

 // Copyright (c) 2012 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_VIEWS_WINDOW_CUSTOM_FRAME_VIEW_H_
 #define UI_VIEWS_WINDOW_CUSTOM_FRAME_VIEW_H_
 
 #include <memory>
 
 #include "base/compiler_specific.h"
@@ skipping 28 matching lines @@
   // Overridden from NonClientFrameView:
   gfx::Rect GetBoundsForClientView() const override;
   gfx::Rect GetWindowBoundsForClientBounds(
       const gfx::Rect& client_bounds) const override;
   int NonClientHitTest(const gfx::Point& point) override;
   void GetWindowMask(const gfx::Size& size, gfx::Path* window_mask) override;
   void ResetWindowControls() override;
   void UpdateWindowIcon() override;
   void UpdateWindowTitle() override;
   void SizeConstraintsChanged() override;
+  void ActivationChanged(bool active) override;
 
   // Overridden from View:
   void OnPaint(gfx::Canvas* canvas) override;
   void Layout() override;
   gfx::Size GetPreferredSize() const override;
   gfx::Size GetMinimumSize() const override;
   gfx::Size GetMaximumSize() const override;
 
   // Overridden from ButtonListener:
   void ButtonPressed(Button* sender, const ui::Event& event) override;
@@ skipping 86 matching lines @@
   ImageButton* close_button_;
 
   // Background painter for the window frame.
   std::unique_ptr<FrameBackground> frame_background_;
 
   // The horizontal boundaries for the title bar to layout within. Restricted
   // by the space used by the leading and trailing buttons.
   int minimum_title_bar_x_;
   int maximum_title_bar_x_;
 
+  // True if the frame containing this frameview is currently active. Updated in
+  // ActivationChanged().
+  bool active_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(CustomFrameView);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_WINDOW_CUSTOM_FRAME_VIEW_H_