Implement DownloadImage directly in WebStateImpl

ios/web/web_state/web_state_impl.h

 // Copyright 2013 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_WEB_STATE_WEB_STATE_IMPL_H_
 #define IOS_WEB_WEB_STATE_WEB_STATE_IMPL_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 25 matching lines @@
 }
 
 namespace web {
 
 class BrowserState;
 struct ContextMenuParams;
 struct Credential;
 struct FaviconURL;
 struct LoadCommittedDetails;
 class NavigationManager;
+class RawImageFetcher;
 class WebInterstitialImpl;
 class WebStateDelegate;
 class WebStateFacadeDelegate;
 class WebStatePolicyDecider;
 class WebUIIOS;
 
 // Implementation of WebState.
 // Generally mirrors //content's WebContents implementation.
 // General notes on expected WebStateImpl ownership patterns:
 //  - Outside of tests, WebStateImpls are created
@@ skipping 306 matching lines @@
   std::map<std::string, ScriptCommandCallback> script_command_callbacks_;
 
   // Member variables should appear before the WeakPtrFactory<> to ensure that
   // any WeakPtrs to WebStateImpl are invalidated before its member variable's
   // destructors are executed, rendering them invalid.
   base::WeakPtrFactory<WebState> weak_factory_;
 
   // Mojo interface registry for this WebState.
   std::unique_ptr<service_manager::InterfaceRegistry> mojo_interface_registry_;
 
+  // Image Fetcher used to download favicons.

[Eugene But (OOO till 7-30), 2016/11/30 17:13:50]

This can download any image, not only favicons. Right?

[gambard, 2016/12/01 15:14:21]

Yes but for now |downloadImage| is only called for favicon.
Done.

+  std::unique_ptr<RawImageFetcher> image_fetcher_;
+
   DISALLOW_COPY_AND_ASSIGN(WebStateImpl);
 };
 
 }  // namespace web
 
 #endif  // IOS_WEB_WEB_STATE_WEB_STATE_IMPL_H_