[ios] Moves tab_switcher code out of the ios_internal namespace.

ios/chrome/browser/ui/tab_switcher/tab_switcher_model_unittest.mm

Index: ios/chrome/browser/ui/tab_switcher/tab_switcher_model_unittest.mm
diff --git a/ios/chrome/browser/ui/tab_switcher/tab_switcher_model_unittest.mm b/ios/chrome/browser/ui/tab_switcher/tab_switcher_model_unittest.mm
index 08e5726d5d98630c075e0e801565d256edf56b1d..a7e540c31e21948c4fa74cfcc99981561ac02a8a 100644
--- a/ios/chrome/browser/ui/tab_switcher/tab_switcher_model_unittest.mm
+++ b/ios/chrome/browser/ui/tab_switcher/tab_switcher_model_unittest.mm
@@ -88,15 +88,14 @@ using LightSS = std::vector<LightDS>;
   EXPECT_EQ(1UL, _expectedTagsOfTheSessionsNeedingUpdates.erase(tag));
 }
 
-- (void)localSessionMayNeedUpdate:(ios_internal::SessionType)type {
+- (void)localSessionMayNeedUpdate:(SessionType)type {
   NOTREACHED();
 }
 
 - (void)signInPanelChangedTo:(TabSwitcherSignInPanelsType)panelType {
   NOTREACHED();
 }
-- (CGSize)sizeForItemAtIndex:(NSUInteger)index
-                   inSession:(ios_internal::SessionType)session {
+- (CGSize)sizeForItemAtIndex:(NSUInteger)index inSession:(SessionType)session {
   return CGSizeZero;
 }
 @end