Adding ArcBridge interface for synchronizing brightness settings

components/arc/common/power.mojom

 // Copyright 2015 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.
 
 // Next min version: 3
 
 module arc.mojom;
 
 // Enumerates the types of wake lock the ARC instance can request from the
 // host.
 [Extensible]
 enum DisplayWakeLockType {
   // Does not allow the screen to dim, turn off, or lock; prevents
   // idle suspend.
   BRIGHT = 0,
 
   // Allows dimming the screen, but prevents it from turning off or locking.
   // Also prevents idle suspend.
   DIM = 1
 };
 
 // Next method ID: 3

[Muyuan, 2017/04/05 18:41:08]

Next Method ID = max methodid in interface + 1

[yueli, 2017/04/05 19:59:47]

Done.

 interface PowerHost {
   // Acquire and release wake locks on the host side.
   OnAcquireDisplayWakeLock@0(DisplayWakeLockType type);
   OnReleaseDisplayWakeLock@1(DisplayWakeLockType type);
 
   // Checks if there is a display on.
   [MinVersion=1] IsDisplayOn@2() => (bool is_on);
+
+  // Set screen brightness.

[Muyuan, 2017/04/05 18:41:08]

Same as L22

[yueli, 2017/04/05 19:59:47]

Done.

+  SetBrightness@3(int32 brightness);

[Muyuan, 2017/04/05 18:41:08]

add MinVersion

[Luis Héctor Chávez, 2017/04/05 19:14:40]

Also document the range of |brightness|. I'd rather have you send the brightness
as a percentage to avoid conversions here and do them on Android, so change this
to |double percentage|.

[yueli, 2017/04/05 19:59:46]

Done.

+
+  // Synchronize screen brightness.
+  SyncBrightness@4();

[Muyuan, 2017/04/05 18:41:10]

Same

[Luis Héctor Chávez, 2017/04/05 19:14:40]

Why is this needed? Can't you always send the initial brightness when the
Android side connects?

[victorhsieh0, 2017/04/05 19:14:51]

nit: This name is a bit ambiguous to me.  Would RequestBrightness be more clear?
 Also, would be nice to mention the instance's UpdateBrightness will be called
in the comment.

[yueli, 2017/04/05 19:59:46]

Done.

[yueli, 2017/04/05 21:19:55]

Done.

 };
 
 // Next method ID: 4
 interface PowerInstance {
   // Establishes full-duplex communication with the host.
   Init@0(PowerHost host_ptr);
 
   // Alerts the instance to a change in interactive state.
   [MinVersion=1] SetInteractive@1(bool enabled);
 
   // Called when the system is about to suspend. The callback will be invoked
   // when pre-suspend work is complete.
   [MinVersion=2] Suspend@2() => ();
 
   // Called when the system has just resumed.
   [MinVersion=2] Resume@3();
+
+  // Update android brightness settings.
+  UpdateBrightness@4(int32 brightness);

[Muyuan, 2017/04/05 18:41:08]

Same as L32

[Luis Héctor Chávez, 2017/04/05 19:14:40]

Same as L32: please send the brightness as a double percentage.

[yueli, 2017/04/05 19:59:46]

Done.

 };