Cleaned up unused methods from WebStateImpl and NavigationContextImpl.

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 acd420c138e5f802766d70d2a6bbd6a8d0aeab17..387f48707501ac05dcc7bc106fd46370049c374a 100644
--- a/ios/web/web_state/web_state_impl.mm
+++ b/ios/web/web_state/web_state_impl.mm
@@ -165,29 +165,6 @@ void WebStateImpl::SetWebController(CRWWebController* web_controller) {
   web_controller_.reset([web_controller retain]);
 }
 
-void WebStateImpl::OnNavigationCommitted(const GURL& url) {
-  std::unique_ptr<NavigationContext> context =
-      NavigationContextImpl::CreateNavigationContext(this, url,
-                                                     GetHttpResponseHeaders());
-  for (auto& observer : observers_)
-    observer.DidFinishNavigation(context.get());
-}
-
-void WebStateImpl::OnSameDocumentNavigation(const GURL& url) {
-  std::unique_ptr<NavigationContext> context =
-      NavigationContextImpl::CreateSameDocumentNavigationContext(this, url);
-  for (auto& observer : observers_)
-    observer.DidFinishNavigation(context.get());
-}
-
-void WebStateImpl::OnErrorPageNavigation(const GURL& url) {
-  std::unique_ptr<NavigationContext> context =
-      NavigationContextImpl::CreateErrorPageNavigationContext(
-          this, url, GetHttpResponseHeaders());
-  for (auto& observer : observers_)
-    observer.DidFinishNavigation(context.get());
-}
-
 void WebStateImpl::OnTitleChanged() {
   for (auto& observer : observers_)
     observer.TitleWasSet();