Handles users rotating screen too early

ash/rotator/screen_rotation_animator_observer.h

Index: ash/rotator/screen_rotation_animator_observer.h
diff --git a/ash/rotator/screen_rotation_animator_observer.h b/ash/rotator/screen_rotation_animator_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..49bd9247904fe9a2510711efdffc224054091c4d
--- /dev/null
+++ b/ash/rotator/screen_rotation_animator_observer.h
@@ -0,0 +1,27 @@
+// Copyright 2017 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_ROTATOR_SCREEN_ROTATION_ANIMATOR_OBSERVER_H
+#define ASH_ROTATOR_SCREEN_ROTATION_ANIMATOR_OBSERVER_H
+
+#include "ash/ash_export.h"
+
+namespace ash {
+
+class ScreenRotationAnimator;
+
+class ASH_EXPORT ScreenRotationAnimatorObserver {
+ public:
+  ScreenRotationAnimatorObserver(){};

[oshima, 2017/03/16 20:13:10]

space between () and {}

[wutao, 2017/03/17 00:01:03]

Added several times, but cl format removed it. I will make sure add it back.

+
+  virtual void OnEndedOrAbortedScreenRotationAnimation(

[oshima, 2017/03/16 20:13:09]

document this.

[wutao, 2017/03/17 00:01:03]

Done.

+      ScreenRotationAnimator* animator){};

[oshima, 2017/03/16 20:13:09]

since this is the only one, make it pure virtual.

[wutao, 2017/03/17 00:01:03]

Done.

+
+ protected:
+  virtual ~ScreenRotationAnimatorObserver(){};

[oshima, 2017/03/16 20:13:09]

ditto.

[wutao, 2017/03/17 00:01:03]

Done.

+};
+
+}  // namespace ash
+
+#endif  // ASH_ROTATOR_SCREEN_ROTATION_ANIMATOR_OBSERVER_H