Initialize PowerMonitor on_power_battery initial value for newly created processes.

Adding an Init method to the Broadcaster, that gets invoked while initializing the host.
The Init method broadcasts the original on_power_battery value to the new processes.

BUG=153139

Review URL: https://codereview.chromium.org/401083002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@284599 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/browser_child_process_host_impl.cc

@@ -106,6 +106,8 @@ BrowserChildProcessHostImpl::BrowserChildProcessHostImpl(
 
   g_child_process_list.Get().push_back(this);
   GetContentClient()->browser()->BrowserChildProcessHostCreated(this);
+
+  power_monitor_message_broadcaster_.Init();
 }
 
 BrowserChildProcessHostImpl::~BrowserChildProcessHostImpl() {

content/browser/power_monitor_message_broadcaster.cc

@@ -24,6 +24,13 @@ PowerMonitorMessageBroadcaster::~PowerMonitorMessageBroadcaster() {
     power_monitor->RemoveObserver(this);
 }
 
+void PowerMonitorMessageBroadcaster::Init() {
+  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
+  // Unit tests does not initialize the PowerMonitor.
+  if (power_monitor)
+    OnPowerStateChange(power_monitor->IsOnBatteryPower());
+}
+
 void PowerMonitorMessageBroadcaster::OnPowerStateChange(bool on_battery_power) {
   sender_->Send(new PowerMonitorMsg_PowerStateChange(on_battery_power));
 }

content/browser/power_monitor_message_broadcaster.h

@@ -28,6 +28,8 @@ class CONTENT_EXPORT PowerMonitorMessageBroadcaster
   virtual void OnSuspend() OVERRIDE;
   virtual void OnResume() OVERRIDE;
 
+  void Init();
+
  private:
   IPC::Sender* sender_;
 

content/browser/power_monitor_message_broadcaster_unittest.cc

@@ -69,6 +69,10 @@ TEST_F(PowerMonitorMessageBroadcasterTest, PowerMessageBroadcast) {
   PowerMonitorMessageSender sender;
   PowerMonitorMessageBroadcaster broadcaster(&sender);
 
+  // Calling Init should invoke a power state change.
+  broadcaster.Init();
+  EXPECT_EQ(sender.power_state_changes(), 1);
+
   // Sending resume when not suspended should have no effect.
   source()->GenerateResumeEvent();
   EXPECT_EQ(sender.resumes(), 0);
@@ -91,19 +95,19 @@ TEST_F(PowerMonitorMessageBroadcasterTest, PowerMessageBroadcast) {
 
   // Pretend the device has gone on battery power
   source()->GeneratePowerStateEvent(true);
-  EXPECT_EQ(sender.power_state_changes(), 1);
+  EXPECT_EQ(sender.power_state_changes(), 2);
 
   // Repeated indications the device is on battery power should be suppressed.
   source()->GeneratePowerStateEvent(true);
-  EXPECT_EQ(sender.power_state_changes(), 1);
+  EXPECT_EQ(sender.power_state_changes(), 2);
 
   // Pretend the device has gone off battery power
   source()->GeneratePowerStateEvent(false);
-  EXPECT_EQ(sender.power_state_changes(), 2);
+  EXPECT_EQ(sender.power_state_changes(), 3);
 
   // Repeated indications the device is off battery power should be suppressed.
   source()->GeneratePowerStateEvent(false);
-  EXPECT_EQ(sender.power_state_changes(), 2);
+  EXPECT_EQ(sender.power_state_changes(), 3);
 }
 
 }  // namespace base

content/browser/renderer_host/render_process_host_impl.cc

@@ -659,6 +659,8 @@ bool RenderProcessHostImpl::Init() {
     GpuDataManagerImpl::GetInstance()->AddObserver(this);
   }
 
+  power_monitor_broadcaster_.Init();
+
   is_initialized_ = true;
   return true;
 }