[fenix] For https://github.com/mozilla-mobile/fenix/issues/8803: hook up frameworkStart metric.

app/src/main/java/org/mozilla/fenix/FenixApplication.kt

@@ -38,6 +38,7 @@ import org.mozilla.fenix.FeatureFlags.webPushIntegration
 import org.mozilla.fenix.components.Components
 import org.mozilla.fenix.components.metrics.MetricServiceType
 import org.mozilla.fenix.ext.settings
+import org.mozilla.fenix.perf.StartupTimeline
 import org.mozilla.fenix.push.PushFxaIntegration
 import org.mozilla.fenix.push.WebPushEngineIntegration
 import org.mozilla.fenix.session.NotificationSessionObserver
@@ -49,6 +50,10 @@ import org.mozilla.fenix.utils.Settings
 @SuppressLint("Registered")
 @Suppress("TooManyFunctions", "LargeClass")
 open class FenixApplication : LocaleAwareApplication() {
+    init {
+        recordOnInit() // DO NOT MOVE ANYTHING ABOVE HERE: the timing of this measurement is critical.
+    }
+
     private val logger = Logger("FenixApplication")
 
     open val components by lazy { Components(this) }
@@ -365,4 +370,10 @@ open class FenixApplication : LocaleAwareApplication() {
             Logger.error("Failed to initialize web extension support", e)
         }
     }
+
+    protected fun recordOnInit() {
+        // This gets called by more than one process. Ideally we'd only run this in the main process
+        // but the code to check which process we're in crashes because the Context isn't valid yet.
+        StartupTimeline.onApplicationInit()
+    }
 }

app/src/main/java/org/mozilla/fenix/HomeActivity.kt

@@ -33,6 +33,7 @@ import mozilla.components.concept.engine.EngineView
 import mozilla.components.feature.contextmenu.ext.DefaultSelectionActionDelegate
 import mozilla.components.service.fxa.sync.SyncReason
 import mozilla.components.support.base.feature.UserInteractionHandler
+import mozilla.components.support.ktx.android.arch.lifecycle.addObservers
 import mozilla.components.support.ktx.android.content.share
 import mozilla.components.support.ktx.kotlin.isUrl
 import mozilla.components.support.ktx.kotlin.toNormalizedUrl
@@ -146,7 +147,10 @@ open class HomeActivity : LocaleAwareAppCompatActivity() {
         }
         supportActionBar?.hide()
 
-        lifecycle.addObserver(webExtensionPopupFeature)
+        lifecycle.addObservers(
+            webExtensionPopupFeature,
+            StartupTimeline.homeActivityLifecycleObserver
+        )
         StartupTimeline.onActivityCreateEndHome(this)
     }
 

app/src/main/java/org/mozilla/fenix/perf/StartupTimeline.kt

@@ -5,8 +5,17 @@
 package org.mozilla.fenix.perf
 
 import androidx.annotation.UiThread
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.LifecycleObserver
+import androidx.lifecycle.OnLifecycleEvent
+import kotlinx.coroutines.GlobalScope
+import kotlinx.coroutines.launch
+import mozilla.components.service.glean.private.NoReasonCodes
+import mozilla.components.service.glean.private.PingType
+import org.mozilla.fenix.GleanMetrics.Pings
 import org.mozilla.fenix.HomeActivity
 import org.mozilla.fenix.home.sessioncontrol.viewholders.topsites.TopSiteItemViewHolder
+import org.mozilla.fenix.perf.StartupTimeline.onApplicationInit
 import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupActivity
 import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupDestination
 import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupState
@@ -20,12 +29,25 @@ import org.mozilla.fenix.perf.StartupTimelineStateMachine.StartupState
  * This class, and its dependencies, may need to be modified for any changes in startup.
  *
  * This class is not thread safe and should only be called from the main thread.
+ *
+ * [onApplicationInit] is called from multiple processes. To minimize overhead, the class
+ * dependencies are lazily initialized.
  */
 @UiThread
 object StartupTimeline {
 
     private var state: StartupState = StartupState.Cold(StartupDestination.UNKNOWN)
-    private val reportFullyDrawn = StartupReportFullyDrawn()
+
+    private val reportFullyDrawn by lazy { StartupReportFullyDrawn() }
+    private val frameworkStartMeasurement by lazy { StartupFrameworkStartMeasurement() }
+    internal val homeActivityLifecycleObserver by lazy {
+        StartupHomeActivityLifecycleObserver(frameworkStartMeasurement)
+    }
+
+    fun onApplicationInit() {
+        // This gets called from multiple processes: don't do anything expensive. See call site for details.
+        frameworkStartMeasurement.onApplicationInit()
+    }
 
     fun onActivityCreateEndIntentReceiver() {
         advanceState(StartupActivity.INTENT_RECEIVER)
@@ -45,3 +67,29 @@ object StartupTimeline {
         state = StartupTimelineStateMachine.getNextState(state, startingActivity)
     }
 }
+
+/**
+ * A [LifecycleObserver] for [HomeActivity] focused on startup performance measurement.
+ */
+internal class StartupHomeActivityLifecycleObserver(
+    private val frameworkStartMeasurement: StartupFrameworkStartMeasurement,
+    private val startupTimeline: PingType<NoReasonCodes> = Pings.startupTimeline
+) : LifecycleObserver {
+
+    @OnLifecycleEvent(Lifecycle.Event.ON_STOP)
+    fun onStop() {
+        GlobalScope.launch { // use background thread due to expensive metrics.
+            // Ensure any last metrics are set before submission.
+            frameworkStartMeasurement.setExpensiveMetric()
+
+            // Startup metrics placed in the Activity should be re-recorded each time the Activity
+            // is started so we need to clear the ping lifetime by submitting once per each startup.
+            // It's less complex to add it here rather than the visual completeness task manager.
+            //
+            // N.B.: this submission location may need to be changed if we add metrics outside of the
+            // HomeActivity startup path (e.g. if the user goes directly to a separate activity and
+            // closes the app, they will never hit this) to appropriately adjust for the ping lifetimes.
+            startupTimeline.submit()
+        }
+    }
+}

app/src/migration/java/org/mozilla/fenix/MigratingFenixApplication.kt

@@ -13,8 +13,9 @@ import org.mozilla.fenix.session.PerformanceActivityLifecycleCallbacks
  * An application class which knows how to migrate Fennec data.
  */
 class MigratingFenixApplication : FenixApplication() {
-
     init {
+        recordOnInit() // DO NOT MOVE ANYTHING ABOVE HERE: the timing of this measurement is critical.
+
         PerformanceActivityLifecycleCallbacks.isTransientActivityInMigrationVariant = {
             if (it is MigrationDecisionActivity) true else false
         }

app/src/test/java/org/mozilla/fenix/perf/StartupHomeActivityLifecycleObserverTest.kt

@@ -0,0 +1,38 @@
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+package org.mozilla.fenix.perf
+
+import io.mockk.MockKAnnotations
+import io.mockk.impl.annotations.MockK
+import io.mockk.verifySequence
+import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.test.runBlockingTest
+import mozilla.components.service.glean.private.NoReasonCodes
+import mozilla.components.service.glean.private.PingType
+import org.junit.Before
+import org.junit.Test
+
+@ExperimentalCoroutinesApi
+class StartupHomeActivityLifecycleObserverTest {
+
+    private lateinit var observer: StartupHomeActivityLifecycleObserver
+    @MockK(relaxed = true) private lateinit var frameworkStartMeasurement: StartupFrameworkStartMeasurement
+    @MockK(relaxed = true) private lateinit var startupTimeline: PingType<NoReasonCodes>
+
+    @Before
+    fun setUp() {
+        MockKAnnotations.init(this)
+        observer = StartupHomeActivityLifecycleObserver(frameworkStartMeasurement, startupTimeline)
+    }
+
+    @Test
+    fun `WHEN onStop is called THEN the metrics are set and the ping is submitted`() = runBlockingTest {
+        observer.onStop()
+        verifySequence {
+            frameworkStartMeasurement.setExpensiveMetric()
+            startupTimeline.submit()
+        }
+    }
+}