Introduce window container to be used by lock screen app windows

ash/wm/lock_window_state.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 ASH_WM_LOCK_WINDOW_STATE_H_
 #define ASH_WM_LOCK_WINDOW_STATE_H_
 
 #include "ash/wm/window_state.h"
 #include "base/macros.h"
 
 namespace ash {
 
 // The LockWindowState implementation which reduces all possible window
 // states to maximized (or normal if can't be maximized)/minimized/full-screen
-// and is applied only on lock (login) window container.
+// and is applied only on lock (login) window container and window containers
+// associated with apps handling lock screen tray actions.
 // LockWindowState implements Ash behavior without state machine.
 class LockWindowState : public wm::WindowState::State {
  public:
   // The |window|'s state object will be modified to use this new window mode
   // state handler.
-  explicit LockWindowState(WmWindow* window);
+  // |shelf_visible| - if set, the maximized window size will be
+  // restricted to work area defined by ash shelf, rather than taking only
+  // virtual keyboard window into consideration when calculating the window
+  // size.
+  LockWindowState(WmWindow* window, bool shelf_visible);
   ~LockWindowState() override;
 
   // WindowState::State overrides:
   void OnWMEvent(wm::WindowState* window_state,
                  const wm::WMEvent* event) override;
   wm::WindowStateType GetType() const override;
   void AttachState(wm::WindowState* window_state,
                    wm::WindowState::State* previous_state) override;
   void DetachState(wm::WindowState* window_state) override;
 
   // Creates new LockWindowState instance and attaches it to |window|.
   static wm::WindowState* SetLockWindowState(WmWindow* window);
+  static wm::WindowState* SetLockWindowStateWithVisibleShelf(WmWindow* window);
 
  private:
   // Updates the window to |new_state_type| and resulting bounds:
   // Either full screen, maximized centered or minimized. If the state does not
   // change, only the bounds will be changed.
   void UpdateWindow(wm::WindowState* window_state,
                     wm::WindowStateType new_state_type);
 
   // Depending on the capabilities of the window we either return
   // |WINDOW_STATE_TYPE_MAXIMIZED| or |WINDOW_STATE_TYPE_NORMAL|.
   wm::WindowStateType GetMaximizedOrCenteredWindowType(
       wm::WindowState* window_state);
 
+  // Returns boudns to be used for the provided window.
+  gfx::Rect GetWindowBounds(aura::Window* window);
+
   // Updates the bounds taking virtual keyboard bounds into consideration.
   void UpdateBounds(wm::WindowState* window_state);
 
   // The current state type. Due to the nature of this state, this can only be
   // WM_STATE_TYPE{NORMAL, MINIMIZED, MAXIMIZED}.
   wm::WindowStateType current_state_type_;
 
+  // Restrict window size to the work area defined by the shelf.
+  bool shelf_visible_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(LockWindowState);
 };
 
 }  // namespace ash
 
 #endif  // ASH_WM_LOCK_WINDOW_STATE_H_