For #19915: Add telemetry for the toolbar Home screen button.

app/metrics.yaml

@@ -433,6 +433,20 @@ events:
     notification_emails:
       - fenix-core@mozilla.com
     expires: "2021-05-10"
+  browser_toolbar_home_tapped:
+    type: event
+    description: |
+      An event that indicates that a user has tapped
+      home button on browser toolbar.
+    bugs:
+      - https://github.com/mozilla-mobile/fenix/issues/19915
+    data_reviews:
+      - https://github.com/mozilla-mobile/fenix/pull/19936
+    data_sensitivity:
+      - interaction
+    notification_emails:
+      - fenix-core@mozilla.com
+    expires: "2021-12-10"
 
 onboarding:
   fxa_auto_signin:

app/src/main/java/org/mozilla/fenix/components/metrics/Event.kt

@@ -236,6 +236,9 @@ sealed class Event {
     object HomeMenuSettingsItemClicked : Event()
     object HomeScreenDisplayed : Event()
 
+    // Browser Toolbar
+    object BrowserToolbarHomeButtonClicked : Event()
+
     // Interaction events with extras
 
     data class TopSiteSwipeCarousel(val page: Int) : Event() {

app/src/main/java/org/mozilla/fenix/components/metrics/GleanMetricsService.kt

@@ -833,6 +833,10 @@ private val Event.wrapper: EventWrapper<*>?
             { HomeScreen.homeScreenDisplayed.record(it) }
         )
 
+        is Event.BrowserToolbarHomeButtonClicked -> EventWrapper<NoExtraKeys>(
+            { Events.browserToolbarHomeTapped.record(it) }
+        )
+
         // Don't record other events in Glean:
         is Event.AddBookmark -> null
         is Event.OpenedAppFirstRun -> null

app/src/main/java/org/mozilla/fenix/components/toolbar/BrowserToolbarController.kt

@@ -164,6 +164,8 @@ class DefaultBrowserToolbarController(
     }
 
     override fun handleHomeButtonClick() {
+        metrics.track(Event.BrowserToolbarHomeButtonClicked)
+
         navController.navigateBlockingForAsyncNavGraph(
             BrowserFragmentDirections.actionGlobalHome()
         )

app/src/test/java/org/mozilla/fenix/components/toolbar/DefaultBrowserToolbarControllerTest.kt

@@ -318,6 +318,7 @@ class DefaultBrowserToolbarControllerTest {
         controller.handleHomeButtonClick()
 
         verify { navController.navigate(BrowserFragmentDirections.actionGlobalHome()) }
+        verify { metrics.track(Event.BrowserToolbarHomeButtonClicked) }
     }
 
     private fun createController(