Use DidFinishNavigation callback in LanguageDetectionController.

ios/web/web_state/web_state_observer_bridge.mm

Index: ios/web/web_state/web_state_observer_bridge.mm
diff --git a/ios/web/web_state/web_state_observer_bridge.mm b/ios/web/web_state/web_state_observer_bridge.mm
index 13fbde3f87782e47fea2739cfd925982626c10d4..bf22c02c364a04eddad275b38d878f6ec1f43ad0 100644
--- a/ios/web/web_state/web_state_observer_bridge.mm
+++ b/ios/web/web_state/web_state_observer_bridge.mm
@@ -67,18 +67,6 @@ void WebStateObserverBridge::InterstitialDismissed() {
     [observer_ webStateDidDismissInterstitial:web_state()];
 }
 
-void WebStateObserverBridge::UrlHashChanged() {
-  SEL selector = @selector(webStateDidChangeURLHash:);
-  if ([observer_ respondsToSelector:selector])
-    [observer_ webStateDidChangeURLHash:web_state()];
-}
-
-void WebStateObserverBridge::HistoryStateChanged() {
-  SEL selector = @selector(webStateDidChangeHistoryState:);
-  if ([observer_ respondsToSelector:selector])
-    [observer_ webStateDidChangeHistoryState:web_state()];
-}
-
 void WebStateObserverBridge::LoadProgressChanged(double progress) {
   SEL selector = @selector(webState:didChangeLoadingProgress:);
   if ([observer_ respondsToSelector:selector])