Download favicon from server for suggested articles

ios/chrome/browser/content_suggestions/content_suggestions_mediator.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/chrome/browser/content_suggestions/content_suggestions_mediator.h"
 
 #include "base/mac/bind_objc_block.h"
 #include "base/memory/ptr_util.h"
 #include "base/optional.h"
 #include "components/favicon/core/large_icon_service.h"
@@ skipping 216 matching lines @@
     }
   }
 }
 
 - (void)fetchFaviconAttributesForURL:(const GURL&)URL
                           completion:(void (^)(FaviconAttributes*))completion {
   [self.attributesProvider fetchFaviconAttributesForURL:URL
                                              completion:completion];
 }
 
+- (void)fetchFaviconImageForSuggestion:(ContentSuggestionIdentifier*)suggestion
+                            completion:(void (^)(UIImage*))completion {
+  if (!completion)
+    return;
+
+  void (^imageCallback)(const gfx::Image&) = ^(const gfx::Image& image) {
+    if (!image.IsEmpty()) {
+      completion([image.ToUIImage() copy]);
+    }
+  };
+
+  ntp_snippets::ContentSuggestion::ID identifier =
+      ntp_snippets::ContentSuggestion::ID(
+          [[self categoryWrapperForSectionInfo:suggestion.sectionInfo]
+              category],
+          suggestion.IDInSection);
+  self.contentService->FetchSuggestionFavicon(
+      identifier, /* minimum_size_in_pixel = */ 1, kDefaultFaviconSize,
+      base::BindBlockArc(imageCallback));
+}
+
 #pragma mark - ContentSuggestionsServiceObserver
 
 - (void)contentSuggestionsService:
             (ntp_snippets::ContentSuggestionsService*)suggestionsService
          newSuggestionsInCategory:(ntp_snippets::Category)category {
   ContentSuggestionsCategoryWrapper* wrapper =
       [ContentSuggestionsCategoryWrapper wrapperWithCategory:category];
   if (!self.sectionInformationByCategory[wrapper]) {
     [self addSectionInformationForCategory:category];
   }
@@ skipping 189 matching lines @@
 }
 
 // Returns whether the |sectionInfo| is associated with a category from the
 // content suggestions service.
 - (BOOL)isRelatedToContentSuggestionsService:
     (ContentSuggestionsSectionInformation*)sectionInfo {
   return sectionInfo != self.mostVisitedSectionInfo;
 }
 
 @end