For #16614 - Ensure a stable order for the items in tabs tray. (#16618)

Items should follow the following ordering:
- current session open tabs
- collections options - currently the "Select tabs" button
- synced tabs items

This order should also be kept after returning from Multiselect mode.

app/src/main/java/org/mozilla/fenix/tabtray/SyncedTabsController.kt

@@ -21,7 +21,6 @@ import mozilla.components.browser.storage.sync.SyncedDeviceTabs
 import mozilla.components.feature.syncedtabs.view.SyncedTabsView
 import mozilla.components.lib.state.ext.flowScoped
 import mozilla.components.support.ktx.kotlinx.coroutines.flow.ifChanged
-import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.sync.ListenerDelegate
 import org.mozilla.fenix.sync.SyncedTabsAdapter
 import org.mozilla.fenix.sync.ext.toAdapterList
@@ -51,11 +50,7 @@ class SyncedTabsController(
                 .collect { mode ->
                     when (mode) {
                         is TabTrayDialogFragmentState.Mode.Normal -> {
-                            if (view.context.settings().gridTabView) {
-                                concatAdapter.addAdapter(adapter)
-                            } else {
-                                concatAdapter.addAdapter(0, adapter)
-                            }
+                            concatAdapter.addAdapter(adapter)
                         }
                         is TabTrayDialogFragmentState.Mode.MultiSelect -> {
                             concatAdapter.removeAdapter(adapter)

app/src/main/java/org/mozilla/fenix/tabtray/TabTrayView.kt

@@ -192,13 +192,8 @@ class TabTrayView(
 
             tabsAdapter.tabTrayInteractor = interactor
             tabsAdapter.onTabsUpdated = {
-                if (view.context.settings().gridTabView) {
-                    concatAdapter.addAdapter(syncedTabsController.adapter)
-                    concatAdapter.addAdapter(collectionsButtonAdapter)
-                } else {
-                    concatAdapter.addAdapter(syncedTabsController.adapter)
-                    concatAdapter.addAdapter(collectionsButtonAdapter)
-                }
+                concatAdapter.addAdapter(collectionsButtonAdapter)
+                concatAdapter.addAdapter(syncedTabsController.adapter)
 
                 if (hasAccessibilityEnabled) {
                     tabsAdapter.notifyItemRangeChanged(0, tabs.size)

app/src/test/java/org/mozilla/fenix/tabtray/SyncedTabsControllerTest.kt

@@ -25,7 +25,6 @@ import org.junit.Rule
 import org.junit.Test
 import org.junit.runner.RunWith
 import org.mozilla.fenix.R
-import org.mozilla.fenix.ext.settings
 import org.mozilla.fenix.helpers.FenixRobolectricTestRunner
 import org.mozilla.fenix.sync.SyncedTabsViewHolder
 import org.mozilla.fenix.tabtray.TabTrayDialogFragmentAction.EnterMultiSelectMode
@@ -56,7 +55,6 @@ class SyncedTabsControllerTest {
 
         concatAdapter = mockk()
         every { concatAdapter.addAdapter(any()) } returns true
-        every { concatAdapter.addAdapter(any(), any()) } returns true
         every { concatAdapter.removeAdapter(any()) } returns true
 
         store = TabTrayDialogFragmentStore(
@@ -130,22 +128,11 @@ class SyncedTabsControllerTest {
 
     @Test
     fun `concatAdapter updated on mode changes`() = testDispatcher.runBlockingTest {
-        // When returning from Multiselect while in grid view the adapter should be added at the end
-        every { view.context.settings().gridTabView } returns true
-
         store.dispatch(EnterMultiSelectMode).joinBlocking()
         verify { concatAdapter.removeAdapter(any()) }
 
         store.dispatch(ExitMultiSelectMode).joinBlocking()
+        // When returning from Multiselect the adapter should be added at the end
         verify { concatAdapter.addAdapter(any()) }
-
-        // When returning from Multiselect while in list view the adapter should be added at the front
-        every { view.context.settings().gridTabView } returns false
-
-        store.dispatch(EnterMultiSelectMode).joinBlocking()
-        verify { concatAdapter.removeAdapter(any()) }
-
-        store.dispatch(ExitMultiSelectMode).joinBlocking()
-        verify { concatAdapter.addAdapter(0, any()) }
     }
 }