Metrics for feature engagement tracker.

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 a04254b2a7871dc3bdb2a6ed1fd46adf0c80d577..b69f41002034d74ffb1cfb962f72f7c7c621a99e 100644
--- a/tools/metrics/histograms/histograms.xml
+++ b/tools/metrics/histograms/histograms.xml
@@ -24642,6 +24642,77 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   </summary>
 </histogram>
 
+<histogram name="InProductHelp.Config.ParsingEvent" enum="ConfigParsingEvent">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+  <summary>
+    Records if in-product help configuration is parsed correctly, and the
+    failure reasons for parsing failures.
+  </summary>
+</histogram>
+
+<histogram base="true" name="InProductHelp.Db.Init" enum="BooleanSuccess">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+<!-- Name completed by histogram_suffixes name="IPHDatabase" -->
+
+  <summary>
+    Records if database initialization succeeds for in-product help.
+  </summary>
+</histogram>
+
+<histogram base="true" name="InProductHelp.Db.Load" enum="BooleanSuccess">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+<!-- Name completed by histogram_suffixes name="IPHDatabase" -->
+
+  <summary>
+    Records if database successfully loads the data for in-product help.
+  </summary>
+</histogram>
+
+<histogram name="InProductHelp.Db.TotalEvents" units="events">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+  <summary>
+    Records the total number of event records in the database for in-product
+    help after the event model is loaded.
+  </summary>
+</histogram>
+
+<histogram base="true" name="InProductHelp.Db.Update" enum="BooleanSuccess">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+<!-- Name completed by histogram_suffixes name="IPHDatabase" -->
+
+  <summary>
+    Records if each database update succeeds for in-product help.
+  </summary>
+</histogram>
+
+<histogram base="true" name="InProductHelp.NotifyEventReadyState"
+    enum="BooleanSuccess">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+<!-- Name completed by histogram_suffixes name="IPHFeatures" -->
+
+  <summary>
+    Records if the model is ready when in-product help event happens.
+  </summary>
+</histogram>
+
+<histogram base="true" name="InProductHelp.ShouldTriggerHelpUI"
+    enum="TriggerHelpUIResult">
+  <owner>nyquist@chromium.org</owner>
+  <owner>xingliu@chromium.org</owner>
+<!-- Name completed by histogram_suffixes name="IPHFeatures" -->
+
+  <summary>
+    Records if in-product help is shown to the user, and the failure reasons if
+    in-product help is not shown.
+  </summary>
+</histogram>
+
 <histogram name="InputMethod.ActiveCount">
   <owner>shuchen@chromium.org</owner>
   <summary>
@@ -87961,6 +88032,23 @@ http://cs/file:chrome/histograms.xml - but prefer this file for new entries.
   <affected-histogram name="Tabs.iOS_PostRedirectPLT"/>
 </histogram_suffixes>
 
+<histogram_suffixes name="IPHDatabase" separator=".">
+  <affected-histogram name="InProductHelp.Db.Init"/>
+  <affected-histogram name="InProductHelp.Db.Load"/>
+  <affected-histogram name="InProductHelp.Db.Update"/>
+  <suffix name="EventStore" label="Event store."/>
+  <suffix name="AvailabilityStore" label="Availability store."/>
+</histogram_suffixes>
+
+<histogram_suffixes name="IPHFeatures" separator=".">
+  <affected-histogram name="InProductHelp.NotifyEventReadyState"/>
+  <affected-histogram name="InProductHelp.ShouldTriggerHelpUI"/>
+  <suffix name="IPH_DataSaverPreview"
+      label="In product help data saver preview."/>
+  <suffix name="IPH_DownloadPage" label="In product help download page."/>
+  <suffix name="IPH_DownloadHome" label="In product help download home."/>
+</histogram_suffixes>
+
 <histogram_suffixes name="IPProtocolType" separator="_">
   <suffix name="UDP"/>
   <suffix name="TCP"/>