Adding ArcBridge interface for synchronizing brightness settings

components/arc/common/power.mojom

Index: components/arc/common/power.mojom
diff --git a/components/arc/common/power.mojom b/components/arc/common/power.mojom
index 195c7c828e391bbe58138f3472b98c25ba54b0cf..fbfe9cdf958b31c79c55df046882e9413db1c98a 100644
--- a/components/arc/common/power.mojom
+++ b/components/arc/common/power.mojom
@@ -19,7 +19,7 @@ enum DisplayWakeLockType {
   DIM = 1
 };
 
-// Next method ID: 3
+// Next method ID: 4
 interface PowerHost {
   // Acquire and release wake locks on the host side.
   OnAcquireDisplayWakeLock@0(DisplayWakeLockType type);
@@ -27,9 +27,13 @@ interface PowerHost {
 
   // Checks if there is a display on.
   [MinVersion=1] IsDisplayOn@2() => (bool is_on);
+
+  // Set screen brightness.
+  // |percent| is of the range [0, 100]
+  [MinVersion=2] SetBrightness@3(double percent);

[Luis Héctor Chávez, 2017/04/05 23:55:27]

MinVersion=3

(all the modifications in this change need to use the same MinVersion. Your
version is 3).

Also, how about you change this to

// Requests that the screen brightness be changed to |percent|.
[MinVersion=3] OnScreenBrightnessUpdateRequest@3(double percent).

[yueli, 2017/04/06 01:12:36]

Done.

 };
 
-// Next method ID: 4
+// Next method ID: 5
 interface PowerInstance {
   // Establishes full-duplex communication with the host.
   Init@0(PowerHost host_ptr);
@@ -43,4 +47,8 @@ interface PowerInstance {
 
   // Called when the system has just resumed.
   [MinVersion=2] Resume@3();
+
+  // Update android brightness settings.

[Daniel Erat, 2017/04/05 23:43:38]

nit: s/android/Android/

+  // |percent| is of the range [0, 100]
+  [MinVersion=3] UpdateBrightness@4(double percent);

[Daniel Erat, 2017/04/05 23:43:38]

would UpdateBrightnessSettings be clearer? it's hard to know from the method
name that this just updates the settings without updating the actual display
brightness.

[Luis Héctor Chávez, 2017/04/05 23:55:27]

Can you also throw in "Screen" somewhere in the method name?

[yueli, 2017/04/06 01:12:37]

Done.

 };