Use IOSImageDataFetcherWrapper for favicon

components/image_fetcher/ios/ios_image_data_fetcher_wrapper.h

 // 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.
 
 #ifndef COMPONENTS_IMAGE_FETCHER_IOS_IOS_IMAGE_DATA_FETCHER_WRAPPER_H_
 #define COMPONENTS_IMAGE_FETCHER_IOS_IOS_IMAGE_DATA_FETCHER_WRAPPER_H_
 
 #import <Foundation/Foundation.h>
 
 #include "base/memory/ref_counted.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/image_fetcher/image_data_fetcher.h"
 
 namespace base {
 class TaskRunner;
 }
 
 namespace net {
 class URLRequestContextGetter;
 }
 
 class GURL;
 
 namespace image_fetcher {
 
-// Callback that informs of the download of an image encoded in |data|.
+// Callback that informs of the download of an image encoded in |data| and the
+// associated metadata. If an error prevented a http response,
+// |metadata.http_response_code| will be RESPONSE_CODE_INVALID.
 using IOSImageDataFetcherCallback = void (^)(NSData* data,
                                              const RequestMetadata& metadata);
 
 class IOSImageDataFetcherWrapper {
  public:
   using DataUseServiceName = data_use_measurement::DataUseUserData::ServiceName;
 
   // The TaskRunner is used to decode the image if it is WebP-encoded.
   IOSImageDataFetcherWrapper(
       net::URLRequestContextGetter* url_request_context_getter,
@@ skipping 27 matching lines @@
   // The task runner used to decode images if necessary.
   const scoped_refptr<base::TaskRunner> task_runner_;
   ImageDataFetcher image_data_fetcher_;
 
   DISALLOW_COPY_AND_ASSIGN(IOSImageDataFetcherWrapper);
 };
 
 }  // namespace image_fetcher
 
 #endif  // COMPONENTS_IMAGE_FETCHER_IOS_IOS_IMAGE_DATA_FETCHER_WRAPPER_H_