ash: Start/stop observing KeyboardController via ShellObserver

ash/common/shelf/shelf_layout_manager.h

 // Copyright 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 ASH_COMMON_SHELF_SHELF_LAYOUT_MANAGER_H_
 #define ASH_COMMON_SHELF_SHELF_LAYOUT_MANAGER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
 #include "ash/common/session/session_state_observer.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/shell_observer.h"
 #include "ash/common/wm/dock/docked_window_layout_manager_observer.h"
 #include "ash/common/wm/lock_state_observer.h"
 #include "ash/common/wm/wm_snap_to_pixel_layout_manager.h"
 #include "ash/common/wm/workspace/workspace_types.h"
 #include "ash/public/cpp/shelf_types.h"
 #include "base/macros.h"
 #include "base/observer_list.h"
+#include "base/scoped_observer.h"
 #include "base/timer/timer.h"
 #include "ui/gfx/geometry/insets.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/keyboard/keyboard_controller_observer.h"
 #include "ui/wm/public/activation_change_observer.h"
 
+namespace keyboard {
+class KeyboardController;
+}
+
 namespace ui {
 class ImplicitAnimationObserver;
 class MouseEvent;
 }
 
 namespace ash {
 
 enum class AnimationChangeType;
 class PanelLayoutManagerTest;
 class ShelfLayoutManagerObserver;
@@ skipping 136 matching lines @@
     return wm_shelf_->IsHorizontalAlignment() ? horizontal : vertical;
   }
 
   // Returns how the shelf background should be painted.
   ShelfBackgroundType GetShelfBackgroundType() const;
 
   // Set the height of the ChromeVox panel, which takes away space from the
   // available work area from the top of the screen.
   void SetChromeVoxPanelHeight(int height);
 
+  void StartObservingKeyboard(
+      keyboard::KeyboardController* keyboard_controller);
+  void StopObservingKeyboard(keyboard::KeyboardController* keyboard_controller);
+
  private:
   class UpdateShelfObserver;
   friend class PanelLayoutManagerTest;
   friend class ShelfLayoutManagerTest;
   friend class WebNotificationTrayTest;
 
   struct TargetBounds {
     TargetBounds();
     ~TargetBounds();
 
@@ skipping 158 matching lines @@
   // needs to be removed from the available work area.
   int chromevox_panel_height_;
 
   // The show hide animation duration override or 0 for default.
   int duration_override_in_ms_;
 
   // The current shelf background. Should not be assigned to directly, use
   // MaybeUpdateShelfBackground() instead.
   ShelfBackgroundType shelf_background_type_;
 
+  ScopedObserver<keyboard::KeyboardController,
+                 keyboard::KeyboardControllerObserver>
+      keyboard_observer_;
+
   DISALLOW_COPY_AND_ASSIGN(ShelfLayoutManager);
 };
 
 }  // namespace ash
 
 #endif  // ASH_COMMON_SHELF_SHELF_LAYOUT_MANAGER_H_