Use DidFinishNavigation callback in LanguageDetectionController.

ios/web/web_state/web_state_impl.h

Index: ios/web/web_state/web_state_impl.h
diff --git a/ios/web/web_state/web_state_impl.h b/ios/web/web_state/web_state_impl.h
index 4b7754ae69ad58cd33451082f61d7507576881a6..5d4f0e8959ec871a37dcd06b3a1bff535e2fbe85 100644
--- a/ios/web/web_state/web_state_impl.h
+++ b/ios/web/web_state/web_state_impl.h
@@ -82,12 +82,6 @@ class WebStateImpl : public WebState, public NavigationManagerDelegate {
   // Called when a navigation is committed.
   void OnNavigationCommitted(const GURL& url);
 
-  // Notifies the observers that the URL hash of the current page changed.
-  void OnUrlHashChanged();
-
-  // Notifies the observers that the history state of the current page changed.
-  void OnHistoryStateChanged();
-
   // Notifies the observers that same page navigation did finish.
   void OnSamePageNavigation(const GURL& url);