Cleaned up unused methods from WebStateImpl and NavigationContextImpl.

ios/web/public/test/fakes/crw_test_web_state_observer.mm

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #import "ios/web/public/test/fakes/crw_test_web_state_observer.h"
 
 #include "base/memory/ptr_util.h"
 #include "ios/web/public/web_state/navigation_context.h"
 #include "ios/web/web_state/navigation_context_impl.h"
 #include "net/http/http_response_headers.h"
@@ skipping 126 matching lines @@
 - (void)webState:(web::WebState*)webState
     didCommitNavigationWithDetails:
         (const web::LoadCommittedDetails&)load_details {
   _commitNavigationInfo = base::MakeUnique<web::TestCommitNavigationInfo>();
   _commitNavigationInfo->web_state = webState;
   _commitNavigationInfo->load_details = load_details;
 }
 
 - (void)webState:(web::WebState*)webState
     didFinishNavigation:(web::NavigationContext*)navigation {
+  ASSERT_TRUE(!navigation->IsErrorPage() || !navigation->IsSameDocument());
   _didFinishNavigationInfo =
       base::MakeUnique<web::TestDidFinishNavigationInfo>();
   _didFinishNavigationInfo->web_state = webState;
-  if (navigation->IsSameDocument()) {
-    ASSERT_FALSE(navigation->IsErrorPage());
-    _didFinishNavigationInfo->context =
-        web::NavigationContextImpl::CreateSameDocumentNavigationContext(
-            navigation->GetWebState(), navigation->GetUrl());
-  } else if (navigation->IsErrorPage()) {
-    ASSERT_FALSE(navigation->IsSameDocument());
-    _didFinishNavigationInfo->context =
-        web::NavigationContextImpl::CreateErrorPageNavigationContext(
-            navigation->GetWebState(), navigation->GetUrl(),
-            navigation->GetResponseHeaders());
-  } else {
-    _didFinishNavigationInfo->context =
-        web::NavigationContextImpl::CreateNavigationContext(
-            navigation->GetWebState(), navigation->GetUrl(),
-            navigation->GetResponseHeaders());
-  }
+  std::unique_ptr<web::NavigationContextImpl> context =
+      web::NavigationContextImpl::CreateNavigationContext(
+          navigation->GetWebState(), navigation->GetUrl());
+  context->SetIsSameDocument(navigation->IsSameDocument());
+  context->SetIsErrorPage(navigation->IsErrorPage());
+  _didFinishNavigationInfo->context = std::move(context);
 }
 
 - (void)webState:(web::WebState*)webState didLoadPageWithSuccess:(BOOL)success {
   _loadPageInfo = base::MakeUnique<web::TestLoadPageInfo>();
   _loadPageInfo->web_state = webState;
   _loadPageInfo->success = success;
 }
 
 - (void)webStateDidDismissInterstitial:(web::WebState*)webState {
   _dismissInterstitialInfo =
@@ skipping 72 matching lines @@
   _stopLoadingInfo = base::MakeUnique<web::TestStopLoadingInfo>();
   _stopLoadingInfo->web_state = webState;
 }
 
 - (void)webStateDidStartLoading:(web::WebState*)webState {
   _startLoadingInfo = base::MakeUnique<web::TestStartLoadingInfo>();
   _startLoadingInfo->web_state = webState;
 }
 
 @end