Bug 1769255 - record the battery percentrage for each active tick, r=chutten,smaug.

Differential Revision: https://phabricator.services.mozilla.com/D146319

dom/events/EventStateManager.cpp

@@ -12,6 +12,7 @@
 #include "mozilla/EventDispatcher.h"
 #include "mozilla/EventForwards.h"
 #include "mozilla/EventStates.h"
+#include "mozilla/Hal.h"
 #include "mozilla/HTMLEditor.h"
 #include "mozilla/IMEStateManager.h"
 #include "mozilla/MiscEvents.h"
@@ -42,6 +43,7 @@
 #include "mozilla/dom/UIEventBinding.h"
 #include "mozilla/dom/UserActivation.h"
 #include "mozilla/dom/WheelEventBinding.h"
+#include "mozilla/glean/GleanMetrics.h"
 #include "mozilla/StaticPrefs_accessibility.h"
 #include "mozilla/StaticPrefs_browser.h"
 #include "mozilla/StaticPrefs_dom.h"
@@ -185,6 +187,13 @@ UITimerCallback::Notify(nsITimer* aTimer) {
   } else {
     obs->NotifyObservers(nullptr, "user-interaction-active", nullptr);
     EventStateManager::UpdateUserActivityTimer();
+
+    if (XRE_IsParentProcess()) {
+      hal::BatteryInformation batteryInfo;
+      hal::GetCurrentBatteryInformation(&batteryInfo);
+      glean::power_battery::percentage_when_user_active.AccumulateSamples(
+          {uint64_t(batteryInfo.level() * 100)});
+    }
   }
   mPreviousCount = gMouseOrKeyboardEventCounter;
   return NS_OK;

toolkit/components/processtools/metrics.yaml

@@ -291,3 +291,25 @@ power.cpu_ms_per_thread:
   content_foreground: *per_thread_cpu_ms
   content_background: *per_thread_cpu_ms
   gpu_process: *per_thread_cpu_ms
+
+power.battery:
+  percentage_when_user_active:
+    type: custom_distribution
+    description: >
+      Records how many percent of battery was available for each period of
+      user activity.
+    range_min: 0
+    range_max: 100
+    bucket_count: 100
+    histogram_type: linear
+    unit: percent
+    bugs:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1769255
+    data_reviews:
+      - https://bugzilla.mozilla.org/show_bug.cgi?id=1769255
+    data_sensitivity:
+      - interaction
+      - technical
+    notification_emails:
+      - florian@mozilla.com
+    expires: never