Tablet-like power button behavior on Convertible/Tablet ChromeOS devices

chromeos/dbus/fake_power_manager_client.cc

Index: chromeos/dbus/fake_power_manager_client.cc
diff --git a/chromeos/dbus/fake_power_manager_client.cc b/chromeos/dbus/fake_power_manager_client.cc
index 6bee1ea7369bfc50732bb4412c02ed2ee6ce210e..c0af43a04691ea511427d9ad700fbce0b396af20 100644
--- a/chromeos/dbus/fake_power_manager_client.cc
+++ b/chromeos/dbus/fake_power_manager_client.cc
@@ -14,7 +14,10 @@ namespace chromeos {
 
 namespace {
 // Minimum power for a USB power source to be classified as AC.
-const double kUsbMinAcWatts = 24;
+constexpr double kUsbMinAcWatts = 24;
+
+// A non-zero brightness used for test.
+constexpr int kNonZeroBrightnessForTest = 10;
 }
 
 FakePowerManagerClient::FakePowerManagerClient()
@@ -137,6 +140,8 @@ void FakePowerManagerClient::SetPowerSource(const std::string& id) {
 
 void FakePowerManagerClient::SetBacklightsForcedOff(bool forced_off) {
   backlights_forced_off_ = forced_off;
+  forced_off ? SendBrightnessChanged(0, true)

[Daniel Erat, 2016/11/10 22:48:55]

please don't call SendBrightnessChanged from here; it makes it impossible to
test other things happening between sending the request and receiving the
notification. tests should be able to call SendBrightnessChanged themselves when
they're ready for the notification to be sent.

[Qiang(Joe) Xu, 2016/11/11 04:39:23]

done by moving to tests.

+             : SendBrightnessChanged(kNonZeroBrightnessForTest, true);
 }
 
 void FakePowerManagerClient::GetBacklightsForcedOff(
@@ -183,6 +188,12 @@ void FakePowerManagerClient::SendDarkSuspendImminent() {
     observer.DarkSuspendImminent();
 }
 
+void FakePowerManagerClient::SendBrightnessChanged(int level,
+                                                   bool user_initiated) {
+  for (auto& observer : observers_)
+    observer.BrightnessChanged(level, user_initiated);
+}
+
 void FakePowerManagerClient::SendPowerButtonEvent(
     bool down,
     const base::TimeTicks& timestamp) {