For #19804: Restore logic to original behavior

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

@@ -311,7 +311,7 @@ open class HomeActivity : LocaleAwareAppCompatActivity(), NavHostActivity {
             }
         }
 
-        trackDefaultBrowser()
+        isFenixTheDefaultBrowser()
     }
 
     override fun onStart() = PerfStartup.homeActivityOnStart.measureNoInline {
@@ -946,11 +946,11 @@ open class HomeActivity : LocaleAwareAppCompatActivity(), NavHostActivity {
         }
     }
 
-    private fun trackDefaultBrowser(){
+    private fun isFenixTheDefaultBrowser() {
         // Launch this on a background thread so as not to affect startup performance
         lifecycleScope.launch(IO) {
             if (
-                settings().checkDefaultBrowserAndSet()
+                settings().checkIfFenixIsDefaultBrowserOnAppResume()
             ) {
                 metrics.track(Event.ChangedToDefaultBrowser)
             }

app/src/main/java/org/mozilla/fenix/components/ReviewPromptController.kt

@@ -30,7 +30,7 @@ class FenixReviewSettings(
         get() = settings.numberOfAppLaunches
         set(value) { settings.numberOfAppLaunches = value }
     override val isDefaultBrowser: Boolean
-        get() = settings.isDefaultBrowser()
+        get() = settings.isDefaultBrowserBlocking()
     override var lastReviewPromptTimeInMillis: Long
         get() = settings.lastReviewPromptTimeInMillis
         set(value) { settings.lastReviewPromptTimeInMillis = value }

app/src/main/java/org/mozilla/fenix/utils/Settings.kt

@@ -471,22 +471,24 @@ class Settings(private val appContext: Context) : PreferencesHolder {
     )
 
     /**
-     * Declared as a function for performance purposes. When this class is first initialized, the
+     * Declared as a function for performance purposes. This could be declared as a variable using
-     * isDefaultBrowser function takes approx. 30-40ms.
+     * booleanPreference like other members of this class. However, doing so will make it so it will
+     * be initialized once Settings.kt is first called, which in turn will call `isDefaultBrowserBlocking()`.
+     * This will lead to a performance regression since that function can be expensive to call.
      */
-    fun checkDefaultBrowserAndSet(): Boolean {
+    fun checkIfFenixIsDefaultBrowserOnAppResume(): Boolean {
         val prefKey = appContext.getPreferenceKey(R.string.pref_key_default_browser)
-        val isDefaultBrowserNow = isDefaultBrowser()
+        val isDefaultBrowserNow = isDefaultBrowserBlocking()
-        val isDefaultBrowserBefore = this.preferences.getBoolean(prefKey, isDefaultBrowserNow)
+        val wasDefaultBrowserOnLastResume = this.preferences.getBoolean(prefKey, isDefaultBrowserNow)
         this.preferences.edit().putBoolean(prefKey, isDefaultBrowserNow).apply()
-        return isDefaultBrowserNow != isDefaultBrowserBefore
+        return isDefaultBrowserNow && !wasDefaultBrowserOnLastResume
     }
 
     /**
      * This function is "blocking" since calling this can take approx. 30-40ms (timing taken on a
      * G5+).
      */
-    private fun isDefaultBrowserBlocking(): Boolean {
+    fun isDefaultBrowserBlocking(): Boolean {
         val browsers = BrowsersCache.all(appContext)
         return browsers.isDefaultBrowser
     }
@@ -497,7 +499,7 @@ class Settings(private val appContext: Context) : PreferencesHolder {
     )
 
     fun shouldShowDefaultBrowserNotification(): Boolean {
-        return !defaultBrowserNotificationDisplayed && !isDefaultBrowser()
+        return !defaultBrowserNotificationDisplayed && !isDefaultBrowserBlocking()
     }
 
     val shouldUseAutoBatteryTheme by booleanPreference(

app/src/test/java/org/mozilla/fenix/utils/SettingsTest.kt

@@ -749,7 +749,7 @@ class SettingsTest {
     @Test
     fun `GIVEN shownDefaultBrowserNotification and isDefaultBrowser WHEN calling shouldShowDefaultBrowserNotification THEN return correct value`() {
         val localSetting = spyk(settings)
-        every { localSetting.isDefaultBrowser() } returns false
+        every { localSetting.isDefaultBrowserBlocking() } returns false
 
         localSetting.defaultBrowserNotificationDisplayed = false
         assert(localSetting.shouldShowDefaultBrowserNotification())
@@ -757,7 +757,7 @@ class SettingsTest {
         localSetting.defaultBrowserNotificationDisplayed = true
         assertFalse(localSetting.shouldShowDefaultBrowserNotification())
 
-        every { localSetting.isDefaultBrowser() } returns true
+        every { localSetting.isDefaultBrowserBlocking() } returns true
 
         localSetting.defaultBrowserNotificationDisplayed = false
         assertFalse(localSetting.shouldShowDefaultBrowserNotification())