Adding ArcBridge interface for synchronizing brightness settings

components/arc/power/arc_power_bridge.cc

Index: components/arc/power/arc_power_bridge.cc
diff --git a/components/arc/power/arc_power_bridge.cc b/components/arc/power/arc_power_bridge.cc
index a9a47f52230fa89212c416b9dfca5a0d4cbbd55d..5bb17fa63bb87d36a6cb2581493ccf6f2861759f 100644
--- a/components/arc/power/arc_power_bridge.cc
+++ b/components/arc/power/arc_power_bridge.cc
@@ -34,6 +34,9 @@ void ArcPowerBridge::OnInstanceReady() {
   ash::Shell::GetInstance()->display_configurator()->AddObserver(this);
   chromeos::DBusThreadManager::Get()->GetPowerManagerClient()->
       AddObserver(this);
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->SyncScreenBrightness();

[Luis Héctor Chávez, 2017/04/05 21:28:02]

You don't need SyncScreenBrightness() either :) Instead you can do

chromeos::DBusThreadManager::Get()
  ->GetPowerManagerClient()
  ->GetGetScreenBrightnessPercent(
     base::Bind(&ArcPowerBridge::UpdateBrightness,
                weak_ptr_factory_.GetWeakPtr()));

then declare a private method

void ArcPowerBridge::UpdateBrightness(double percent) {
   mojom::PowerInstance* power_instance = ARC_GET_INSTANCE_FOR_METHOD(
       arc_bridge_service()->power(), UpdateBrightness);
   if (!power_instance)
     return;
   power_instance->UpdateBrightness(percent);
}

And call it from the callback:

void ArcPowerBridge::BrightnessChanged(int level, double percent) {
  UpdateBrightness(percent);
}

See other places where a base::WeakPtrFactory is used to see how you need to
declare it.

[yueli, 2017/04/05 23:27:17]

Thanks Luis!
Done.

 }
 
 void ArcPowerBridge::OnInstanceClosed() {
@@ -74,6 +77,16 @@ void ArcPowerBridge::OnPowerStateChanged(
   power_instance->SetInteractive(enabled);
 }
 
+void ArcPowerBridge::BrightnessChanged(int level, bool user_initiated) {
+  mojom::PowerInstance* power_instance = ARC_GET_INSTANCE_FOR_METHOD(
+      arc_bridge_service()->power(), UpdateBrightness);
+  if (!power_instance)
+    return;
+  // Android side brightness is of the range [0, 255]
+  int brightness = round(level * 2.55);
+  power_instance->UpdateBrightness(brightness);
+}
+
 void ArcPowerBridge::OnAcquireDisplayWakeLock(mojom::DisplayWakeLockType type) {
   if (!chromeos::PowerPolicyController::IsInitialized()) {
     LOG(WARNING) << "PowerPolicyController is not available";
@@ -126,6 +139,14 @@ void ArcPowerBridge::IsDisplayOn(const IsDisplayOnCallback& callback) {
       ash::Shell::GetInstance()->display_configurator()->IsDisplayOn());
 }
 
+void ArcPowerBridge::SetBrightness(int32_t brightness) {
+  // Android side brightness is of the range [0, 255]
+  chromeos::DBusThreadManager::Get()
+      ->GetPowerManagerClient()
+      ->SetScreenBrightnessPercent(brightness / 2.55, true);
+  return;
+}
+
 void ArcPowerBridge::ReleaseAllDisplayWakeLocks() {
   if (!chromeos::PowerPolicyController::IsInitialized()) {
     LOG(WARNING) << "PowerPolicyController is not available";