[Background Sync] Gather UMA data for Background Sync

tools/metrics/histograms/histograms.xml

Index: tools/metrics/histograms/histograms.xml
diff --git a/tools/metrics/histograms/histograms.xml b/tools/metrics/histograms/histograms.xml
index 01d31bc933a0b18f49f37309773495df8b5cb164..8115c0733692dc15a18e9f44dd775b7f6b3ddf2f 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -2438,6 +2438,69 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="BackgroundSync.Event.OneShotResult" enum="BooleanSuccess">
+  <owner>iclelland@chromium.org</owner>
+  <summary>Records whether a one-shot sync event succeeded or failed.</summary>
+</histogram>
+
+<histogram name="BackgroundSync.Event.PeriodicResult" enum="BooleanSuccess">
+  <owner>iclelland@chromium.org</owner>
+  <summary>Records whether a periodic sync event succeeded or failed.</summary>
+</histogram>
+
+<histogram name="BackgroundSync.Event.Time" units="milliseconds">
+  <owner>iclelland@chromium.org</owner>
+  <summary>Time taken to execute all sync events to completion.</summary>
+</histogram>
+
+<histogram name="BackgroundSync.Registration.OneShot"
+    enum="BackgroundSyncRegistrationResult">
+  <owner>iclelland@chromium.org</owner>
+  <summary>
+    Records the result of attempting to register a one-shot sync.
+  </summary>
+</histogram>
+
+<histogram name="BackgroundSync.Registration.OneShot.CouldFire"
+    enum="BooleanCouldFireImmediately">
+  <owner>iclelland@chromium.org</owner>
+  <summary>
+    Records the result of attempting to register a one-shot sync in a situation
+    where the sync could fire immediately.
+  </summary>
+</histogram>
+
+<histogram name="BackgroundSync.Registration.Periodic"
+    enum="BackgroundSyncRegistrationResult">
+  <owner>iclelland@chromium.org</owner>
+  <summary>
+    Records the result of attempting to register a periodic sync.
+  </summary>
+</histogram>
+
+<histogram name="BackgroundSync.Registration.Periodic.CouldFire"
+    enum="BooleanCouldFireImmediately">
+  <owner>iclelland@chromium.org</owner>
+  <summary>
+    Records the result of attempting to register a periodic sync in a situation
+    where the sync could fire immediately.
+  </summary>
+</histogram>
+
+<histogram name="BackgroundSync.Unregistration.OneShot" enum="BooleanSuccess">
+  <owner>iclelland@chromium.org</owner>
+  <summary>
+    Records the result of attempting to unregister a one-shot sync.
+  </summary>
+</histogram>
+
+<histogram name="BackgroundSync.Unregistration.Periodic" enum="BooleanSuccess">
+  <owner>iclelland@chromium.org</owner>
+  <summary>
+    Records the result of attempting to unregister a periodic sync.
+  </summary>
+</histogram>
+
 <histogram name="BatteryStatus.NumberBatteriesLinux"
     enum="BatteryStatusNumberBatteries">
   <owner>timvolodine@chromium.org</owner>
@@ -50681,6 +50744,12 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="3" label="AUTO_LAUNCH_FOREGROUND_USELESS"/>
 </enum>
 
+<enum name="BackgroundSyncRegistrationResult" type="int">
+  <int value="0" label="REGISTRATION_RESULT_SUCCEEDED"/>
+  <int value="1" label="REGISTRATION_RESULT_FAILED"/>
+  <int value="2" label="REGISTRATION_RESULT_DUPLICATE"/>
+</enum>
+
 <enum name="BackgroundTracingState" type="int">
   <int value="0" label="Scenario activation requested"/>
   <int value="1" label="Scenario successfully activated"/>
@@ -50973,6 +51042,11 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <int value="1" label="Corrupt"/>
 </enum>
 
+<enum name="BooleanCouldFireImmediately" type="int">
+  <int value="0" label="Could not fire immediately"/>
+  <int value="1" label="Could fire immediately"/>
+</enum>
+
 <enum name="BooleanCovered" type="int">
   <int value="0" label="Not Covered"/>
   <int value="1" label="Covered"/>