Use IOSImageDataFetcherWrapper for favicon

ios/web/public/test/fakes/test_web_state.h

 // 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.
 
 #ifndef IOS_WEB_PUBLIC_TEST_FAKES_TEST_WEB_STATE_H_
 #define IOS_WEB_PUBLIC_TEST_FAKES_TEST_WEB_STATE_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 52 matching lines @@
   WebInterstitial* GetWebInterstitial() const override;
   void OnPasswordInputShownOnHttp() override {}
   void OnCreditCardInputShownOnHttp() override {}
 
   void AddObserver(WebStateObserver* observer) override;
 
   void RemoveObserver(WebStateObserver* observer) override;
 
   void AddPolicyDecider(WebStatePolicyDecider* decider) override {}
   void RemovePolicyDecider(WebStatePolicyDecider* decider) override {}
-  int DownloadImage(const GURL& url,
-                    bool is_favicon,
-                    uint32_t max_bitmap_size,
-                    bool bypass_cache,
-                    const ImageDownloadCallback& callback) override;
   service_manager::InterfaceRegistry* GetMojoInterfaceRegistry() override;
   base::WeakPtr<WebState> AsWeakPtr() override;
 
   // Setters for test data.
   void SetContentIsHTML(bool content_is_html);
   void SetLoading(bool is_loading);
   void SetCurrentURL(const GURL& url);
   void SetTrustLevel(URLVerificationTrustLevel trust_level);
   void SetNavigationManager(
       std::unique_ptr<NavigationManager> navigation_manager);
@@ skipping 15 matching lines @@
   std::unique_ptr<NavigationManager> navigation_manager_;
   base::scoped_nsobject<UIView> view_;
 
   // A list of observers notified when page state changes. Weak references.
   base::ObserverList<WebStateObserver, true> observers_;
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_PUBLIC_TEST_FAKES_TEST_WEB_STATE_H_