athena: Improve the overview mode support for split-view mode.

athena/wm/overview_toolbar.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 ATHENA_WM_OVERVIEW_TOOLBAR_H_
 #define ATHENA_WM_OVERVIEW_TOOLBAR_H_
 
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "ui/gfx/geometry/rect.h"
@@ skipping 29 matching lines @@
 
   ActionType current_action() const { return current_action_; }
 
   // Returns the action the gesture-event is targeting.
   ActionType GetHighlightAction(const ui::GestureEvent& event) const;
 
   void SetHighlightAction(ActionType action);
   void ShowActionButtons();
   void HideActionButtons();
 
+  void DisableAction(ActionType action);
+
  private:
   void ToggleActionButtonsVisibility();
+  bool IsActionEnabled(ActionType action) const;
   bool IsEventOverButton(ActionButton* button,
                          const ui::GestureEvent& event) const;
   gfx::Transform ComputeTransformFor(ActionButton* button) const;
   void TransformButton(ActionButton* button);
 
   bool shown_;
+  uint64_t disabled_action_bitfields_;
   scoped_ptr<ActionButton> close_;
   scoped_ptr<ActionButton> split_;
   ActionType current_action_;
   const gfx::Rect container_bounds_;
 
   DISALLOW_COPY_AND_ASSIGN(OverviewToolbar);
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_WM_OVERVIEW_TOOLBAR_H_