Initialize application state in AndroidBatteryMetrics.

AndroidBatteryMetrics required an application state change before
switching from UNKNOWN to the current state, which prevents it from
recording metrics on browser startup immediately.

This CL changes the behavior to check the application state on
startup, so that recording can begin immediately.

Change-Id: Iaec5a175ea3f367b30d1fd95414dcc5e67573315
Bug: 1113311
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2333090
Commit-Queue: Frank Liberato <liberato@chromium.org>
Reviewed-by: Ted Choc <tedchoc@chromium.org>
Reviewed-by: Eric Seckler <eseckler@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795154}

chrome/browser/android/battery/android_battery_metrics.cc

@@ -67,8 +67,11 @@ constexpr base::TimeDelta AndroidBatteryMetrics::kDrainMetricsInterval;
 AndroidBatteryMetrics::AndroidBatteryMetrics()
     : app_state_listener_(base::android::ApplicationStatusListener::New(
           base::BindRepeating(&AndroidBatteryMetrics::OnAppStateChanged,
-                              base::Unretained(this)))) {
+                              base::Unretained(this)))),
+      app_state_(base::android::ApplicationStatusListener::GetState()),
+      on_battery_power_(base::PowerMonitor::IsOnBatteryPower()) {
   base::PowerMonitor::AddObserver(this);
+  UpdateDrainMetricsEnabled();
 }
 
 AndroidBatteryMetrics::~AndroidBatteryMetrics() {

chrome/browser/android/battery/android_battery_metrics.h

@@ -38,9 +38,8 @@ class AndroidBatteryMetrics : public base::PowerObserver {
       base::TimeDelta::FromSeconds(30);
 
   std::unique_ptr<base::android::ApplicationStatusListener> app_state_listener_;
-  base::android::ApplicationState app_state_ =
-      base::android::APPLICATION_STATE_UNKNOWN;
-  bool on_battery_power_ = false;
+  base::android::ApplicationState app_state_;
+  bool on_battery_power_;
   int last_remaining_capacity_uah_ = 0;
   base::RepeatingTimer drain_metrics_timer_;
   int skipped_timers_ = 0;