[Refactor] Move the non-browser specific logic of ImmersiveModeControllerAsh into ash part 2

ash/wm/immersive_revealed_lock.h

+// Copyright 2013 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_IMMERSIVE_REVEALED_LOCK_H_
+#define ASH_WM_IMMERSIVE_REVEALED_LOCK_H_
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "base/memory/weak_ptr.h"
+
+namespace ash {
+
+// Class which keeps the top-of-window views revealed for the duration of its
+// lifetime. If acquiring the lock causes a reveal, the top-of-window views
+// will animate according to the |animate_reveal| parameter passed in the
+// constructor. See ImmersiveFullscreenController::GetRevealedLock() for more
+// details.
+class ASH_EXPORT ImmersiveRevealedLock {
+ public:
+  class ASH_EXPORT Delegate {
+   public:
+    enum AnimateReveal {
+      ANIMATE_REVEAL_YES,
+      ANIMATE_REVEAL_NO
+    };
+
+    virtual void LockRevealedState(AnimateReveal animate_reveal) = 0;
+    virtual void UnlockRevealedState() = 0;
+
+   protected:
+    virtual ~Delegate() {}
+  };
+
+  ImmersiveRevealedLock(const base::WeakPtr<Delegate>& delegate,
+                        Delegate::AnimateReveal animate_reveal);
+  ~ImmersiveRevealedLock();
+
+ private:
+  base::WeakPtr<Delegate> delegate_;
+
+  DISALLOW_COPY_AND_ASSIGN(ImmersiveRevealedLock);
+};
+
+}  // namespace ash
+
+#endif  // ASH_WM_IMMERSIVE_REVEALED_LOCK_H_