[ios] Added web// public API to let embedder observe loading progress.

ios/web/public/test/test_web_state.mm

 // Copyright 2014 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.
 
 #include <stdint.h>
 
 #include "ios/web/public/test/test_web_state.h"
 
 namespace web {
 
 TestWebState::TestWebState()
     : trust_level_(kAbsolute), content_is_html_(true) {}
 
 TestWebState::~TestWebState() = default;
 
 UIView* TestWebState::GetView() {
   return nullptr;
 }
 
+WebStateDelegate* TestWebState::GetDelegate() {
+  return nil;
+}
+
+void TestWebState::SetDelegate(WebStateDelegate* delegate) {}
+
 BrowserState* TestWebState::GetBrowserState() const {
   return nullptr;
 }
 
 NavigationManager* TestWebState::GetNavigationManager() {
   return nullptr;
 }
 
 CRWJSInjectionReceiver* TestWebState::GetJSInjectionReceiver() const {
   return nullptr;
@@ skipping 71 matching lines @@
                                 const ImageDownloadCallback& callback) {
   return 0;
 }
 
 base::WeakPtr<WebState> TestWebState::AsWeakPtr() {
   NOTREACHED();
   return base::WeakPtr<WebState>();
 }
 
 }  // namespace web