Use DidFinishNavigation callback in LanguageDetectionController.

ios/web/web_state/web_state_impl.mm

Index: ios/web/web_state/web_state_impl.mm
diff --git a/ios/web/web_state/web_state_impl.mm b/ios/web/web_state/web_state_impl.mm
index 2a3034f272f460e3f7c54d19262ff7e67add73d9..824affdf48eab72073423c9a2dae5b684c91e4d5 100644
--- a/ios/web/web_state/web_state_impl.mm
+++ b/ios/web/web_state/web_state_impl.mm
@@ -193,16 +193,6 @@ void WebStateImpl::OnNavigationCommitted(const GURL& url) {
     observer.DidFinishNavigation(context.get());
 }
 
-void WebStateImpl::OnUrlHashChanged() {
-  for (auto& observer : observers_)
-    observer.UrlHashChanged();
-}
-
-void WebStateImpl::OnHistoryStateChanged() {
-  for (auto& observer : observers_)
-    observer.HistoryStateChanged();
-}
-
 void WebStateImpl::OnSamePageNavigation(const GURL& url) {
   std::unique_ptr<NavigationContext> context =
       NavigationContextImpl::CreateSamePageNavigationContext(this, url);