Add LockLayoutManager responsible for lock container (login/lock).

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"
+
+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.
+// 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(aura::Window* window);
+  virtual ~LockWindowState();
+
+  // WindowState::State overrides:
+  virtual void OnWMEvent(wm::WindowState* window_state,
+                         const wm::WMEvent* event) OVERRIDE;
+  virtual wm::WindowStateType GetType() const OVERRIDE;
+  virtual void AttachState(wm::WindowState* window_state,
+                           wm::WindowState::State* previous_state) OVERRIDE;
+  virtual void DetachState(wm::WindowState* window_state) OVERRIDE;
+
+  // Creates new LockWindowState instance and attaches it to |window|.
+  static wm::WindowState* SetLockWindowState(aura::Window* 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);
+
+  // 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_;
+
+  DISALLOW_COPY_AND_ASSIGN(LockWindowState);
+};
+
+}  // namespace ash
+
+#endif  // ASH_WM_LOCK_WINDOW_STATE_H_