[glic] Log time between sessions

This CL logs the time elapsed between opening the Glic window.

Fixed: 406819491, 407698313
Bug: 391417447
Change-Id: If7b5c1fa69f14b494d007f116e8fa74d01be6f84
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6415812
Commit-Queue: Filipa Senra <fsenra@google.com>
Reviewed-by: Nicola Tommasi <tommasin@chromium.org>
Reviewed-by: Christian Dullweber <dullweber@chromium.org>
Auto-Submit: Filipa Senra <fsenra@google.com>
Reviewed-by: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1442641}

chrome/browser/glic/glic_metrics.cc

@@ -205,6 +205,23 @@ void GlicMetrics::OnGlicWindowOpen(bool attached,
       .SetAttached(attached)
       .SetInvocationSource(static_cast<int64_t>(source))
       .Record(ukm::UkmRecorder::Get());
+
+  const base::Time last_dismissed_time =
+      profile_->GetPrefs()->GetTime(prefs::kGlicWindowLastDismissedTime);
+  if (!last_dismissed_time.is_null()) {
+    base::TimeDelta elapsed_time_from_last_session =
+        base::Time::Now() - last_dismissed_time;
+    base::UmaHistogramCounts10M(
+        "Glic.PanelWebUi.ElapsedTimeBetweenSessions",
+        base::saturated_cast<int>(elapsed_time_from_last_session.InSeconds()));
+  }
+
+  // Update the last dismissed timestamp. The pref might not get updated on
+  // ungraceful shutdowns. As such, by updating the pref on opening the Glic
+  // window, the dismissal timestamp will get approximated by the opening
+  // timestamp, instead of the previously dismissal timestamp.
+  profile_->GetPrefs()->SetTime(prefs::kGlicWindowLastDismissedTime,
+                                base::Time::Now());
 }
 
 void GlicMetrics::OnGlicWindowOpenAndReady() {
@@ -278,6 +295,8 @@ void GlicMetrics::OnGlicWindowClose() {
   attach_change_count_ = 0;
 
   glic_window_size_timer_.Stop();
+  profile_->GetPrefs()->SetTime(prefs::kGlicWindowLastDismissedTime,
+                                base::Time::Now());
 }
 
 void GlicMetrics::SetControllers(GlicWindowController* window_controller,

chrome/browser/glic/glic_metrics_unittest.cc

@@ -559,5 +559,21 @@ TEST_F(GlicMetricsTest, AttachStateChanges) {
   histogram_tester_.ExpectBucketCount("Glic.Session.AttachStateChanges", 4, 1);
 }
 
+TEST_F(GlicMetricsTest, TimeElapsedBetweenSessions) {
+  base::TimeDelta elapsed_time = base::Hours(2);
+
+  metrics_->OnGlicWindowClose();
+  task_environment_.FastForwardBy(elapsed_time);
+
+  metrics_->OnGlicWindowOpen(/*attached=*/true,
+                             mojom::InvocationSource::kOsButton);
+  histogram_tester_.ExpectTotalCount(
+      "Glic.PanelWebUi.ElapsedTimeBetweenSessions",
+      /*expected_count=*/1);
+  histogram_tester_.ExpectBucketCount(
+      "Glic.PanelWebUi.ElapsedTimeBetweenSessions", elapsed_time.InSeconds(),
+      1);
+}
+
 }  // namespace
 }  // namespace glic

chrome/browser/glic/glic_pref_names.cc

@@ -17,6 +17,7 @@ void RegisterProfilePrefs(PrefRegistrySimple* registry) {
   registry->RegisterBooleanPref(kGlicTabContextEnabled, false);
   registry->RegisterIntegerPref(
       kGlicCompletedFre, static_cast<int>(prefs::FreStatus::kNotStarted));
+  registry->RegisterTimePref(kGlicWindowLastDismissedTime, base::Time());
 }
 
 void RegisterLocalStatePrefs(PrefRegistrySimple* registry) {

chrome/browser/glic/glic_pref_names.h

@@ -62,6 +62,10 @@ inline constexpr char kGlicTabContextEnabled[] = "glic.tab_context_enabled";
 // the FreStatus enum.
 inline constexpr char kGlicCompletedFre[] = "glic.completed_fre";
 
+// Time pref that records the last time a user dismissed the Glic window.
+inline constexpr char kGlicWindowLastDismissedTime[] =
+    "glic.window.last_dimissed_time";
+
 void RegisterProfilePrefs(PrefRegistrySimple* registry);
 void RegisterLocalStatePrefs(PrefRegistrySimple* registry);
 

tools/metrics/histograms/metadata/glic/histograms.xml

@@ -268,6 +268,16 @@ chromium-metrics-reviews@google.com.
   </token>
 </histogram>
 
+<histogram name="Glic.PanelWebUi.ElapsedTimeBetweenSessions" units="seconds"
+    expires_after="2026-01-15">
+  <owner>fsenra@google.com</owner>
+  <owner>dewittj@google.com</owner>
+  <summary>
+    Records the elapsed time between the current and last session. Recorded when
+    the Glic panel is opened.
+  </summary>
+</histogram>
+
 <histogram name="Glic.PanelWebUi.Size.Area" units="DIPs"
     expires_after="2026-01-15">
   <owner>fsenra@google.com</owner>