[Night Light] CL4: Automatic schedule backend.

ash/system/night_light/night_light_time.h

+// 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_SYSTEM_NIGHT_LIGHT_NIGHT_LIGHT_TIME_H_
+#define ASH_SYSTEM_NIGHT_LIGHT_NIGHT_LIGHT_TIME_H_

[James Cook, 2017/05/23 16:34:59]

I think this class should be called TimeOfDay, since that's what it does.

tools/git/move_source_file.py to the rescue!

[afakhry, 2017/05/24 04:21:11]

Done. Eclipse is very good at this! Just Highlight the class, press Alt+Shift+R,
Rename the class, Press Ctrl+Enter, review the changes, Done.

+
+#include <string>
+
+#include "ash/ash_export.h"
+#include "base/time/time.h"
+
+namespace ash {
+
+// Represents the time of the day as a simple number of minutes since 00:00
+// regardless of the date or the timezone. This makes it simple to persist this
+// as an integer user pref.
+class ASH_EXPORT NightLightTime {

[James Cook, 2017/05/23 16:34:59]

Aside: I'm a little surprised we don't already have a time-of-day class, but I
can't find one.

[afakhry, 2017/05/24 04:21:11]

Yes, me too.

+ public:
+  // |offset_minutes| is the number of minutes since 00:00. If |offset_minutes|
+  // is equal to the offset minutes in 24 hours, it will be reset to 0 to
+  // represent the time 00:00 (12:00 AM). Offsets greater than the minutes in
+  // 24 hours are not allowed.
+  explicit NightLightTime(int offset_minutes);
+  NightLightTime(const NightLightTime& other);

[James Cook, 2017/05/23 16:34:59]

Does = default work here?

[afakhry, 2017/05/24 04:21:11]

Yes. Done.

+  ~NightLightTime() = default;
+
+  // Converts to a minutes offset representation from |time| dropping the
+  // seconds and milliseconds.
+  static NightLightTime FromTime(const base::Time& time);
+
+  NightLightTime& operator=(const NightLightTime& rhs);

[James Cook, 2017/05/23 16:34:59]

Does = default work here?

nit: move up near NightLightTime(const NightLightTime&)

[afakhry, 2017/05/24 04:21:11]

Done. I also added a test.

+
+  bool operator==(const NightLightTime& rhs) const;
+
+  int offset_minutes_from_zero_hour() const {
+    return offset_minutes_from_zero_hour_;
+  }
+
+  // Converts to an actual point in time today.
+  base::Time ToTime() const;

[James Cook, 2017/05/23 16:34:59]

This might be clearer as ToTimeToday().

Also, document what happens if the time-of-day doesn't exist. For example, 12:30
AM during daylight savings time.

[afakhry, 2017/05/24 04:21:11]

Done. Check my comment in the .cc file.

+
+  // Converts to a string in the format "3:07 PM".
+  std::string ToString() const;
+
+ private:
+  int offset_minutes_from_zero_hour_;
+};
+
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_NIGHT_LIGHT_NIGHT_LIGHT_TIME_H_