For #21299: add markers for all activity lifecycle callbacks.

We implement these all in the same track because between it'd create a
lot noise between this and fragment lifecycle callbacks.

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

@@ -76,6 +76,7 @@ import org.mozilla.fenix.components.Core
 import org.mozilla.fenix.components.metrics.Event
 import org.mozilla.fenix.components.metrics.MozillaProductDetector
 import org.mozilla.fenix.components.toolbar.ToolbarPosition
+import org.mozilla.fenix.perf.MarkersLifecycleCallbacks
 import org.mozilla.fenix.utils.Settings
 
 /**
@@ -192,6 +193,7 @@ open class FenixApplication : LocaleAwareApplication(), Provider {
 
         visibilityLifecycleCallback = VisibilityLifecycleCallback(getSystemService())
         registerActivityLifecycleCallbacks(visibilityLifecycleCallback)
+        registerActivityLifecycleCallbacks(MarkersLifecycleCallbacks(components.core.engine))
 
         // Storage maintenance disabled, for now, as it was interfering with background migrations.
         // See https://github.com/mozilla-mobile/fenix/issues/7227 for context.

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

@@ -179,9 +179,6 @@ open class HomeActivity : LocaleAwareAppCompatActivity(), NavHostActivity {
     private lateinit var startupTypeTelemetry: StartupTypeTelemetry
 
     final override fun onCreate(savedInstanceState: Bundle?) {
-        // DO NOT MOVE ANYTHING ABOVE THIS addMarker CALL.
-        components.core.engine.profiler?.addMarker("Activity.onCreate", "HomeActivity")
-
         components.strictMode.attachListenerToDisablePenaltyDeath(supportFragmentManager)
         // There is disk read violations on some devices such as samsung and pixel for android 9/10
         components.strictMode.resetAfter(StrictMode.allowThreadDiskReads()) {

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

@@ -30,9 +30,6 @@ class IntentReceiverActivity : Activity() {
 
     @VisibleForTesting
     override fun onCreate(savedInstanceState: Bundle?) {
-        // DO NOT MOVE ANYTHING ABOVE THIS addMarker CALL.
-        components.core.engine.profiler?.addMarker("Activity.onCreate", "IntentReceiverActivity")
-
         // StrictMode violation on certain devices such as Samsung
         components.strictMode.resetAfter(StrictMode.allowThreadDiskReads()) {
             super.onCreate(savedInstanceState)

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

@@ -0,0 +1,59 @@
+/* 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 android.app.Activity
+import android.os.Bundle
+import mozilla.components.concept.engine.Engine
+import org.mozilla.fenix.android.DefaultActivityLifecycleCallbacks
+
+/**
+ * Adds a profiler marker for each activity lifecycle callbacks. The callbacks are called by the
+ * super method (e.g. [Activity.onCreate] so the markers occur sometime during the execution of
+ * our implementation (e.g. [org.mozilla.fenix.HomeActivity.onCreate]) rather than at the beginning
+ * or end of that method.
+ */
+class MarkersLifecycleCallbacks(
+    private val engine: Engine,
+) : DefaultActivityLifecycleCallbacks {
+
+    private fun shouldSkip(): Boolean {
+        return engine.profiler?.isProfilerActive() != true
+    }
+
+    override fun onActivityCreated(activity: Activity, bundle: Bundle?) {
+        if (shouldSkip()) { return }
+        engine.profiler?.addMarker(MARKER_NAME, "${activity::class.simpleName}.onCreate (via callbacks)")
+    }
+
+    override fun onActivityStarted(activity: Activity) {
+        if (shouldSkip()) { return }
+        engine.profiler?.addMarker(MARKER_NAME, "${activity::class.simpleName}.onStart (via callbacks)")
+    }
+
+    override fun onActivityResumed(activity: Activity) {
+        if (shouldSkip()) { return }
+        engine.profiler?.addMarker(MARKER_NAME, "${activity::class.simpleName}.onResume (via callbacks)")
+    }
+
+    override fun onActivityPaused(activity: Activity) {
+        if (shouldSkip()) { return }
+        engine.profiler?.addMarker(MARKER_NAME, "${activity::class.simpleName}.onPause (via callbacks)")
+    }
+
+    override fun onActivityStopped(activity: Activity) {
+        if (shouldSkip()) { return }
+        engine.profiler?.addMarker(MARKER_NAME, "${activity::class.simpleName}.onStop (via callbacks)")
+    }
+
+    override fun onActivityDestroyed(activity: Activity) {
+        if (shouldSkip()) { return }
+        engine.profiler?.addMarker(MARKER_NAME, "${activity::class.simpleName}.onDestroy (via callbacks)")
+    }
+
+    companion object {
+        private const val MARKER_NAME = "Activity Lifecycle"
+    }
+}