Pass UIImage instead of gfx::Image in ContentSuggestions

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 "base/strings/sys_string_conversions.h"
@@ skipping 289 matching lines @@
 
 - (void)contentSuggestionsServiceShutdown:
     (ntp_snippets::ContentSuggestionsService*)suggestionsService {
   // Update dataSink.
 }
 
 #pragma mark - ContentSuggestionsImageFetcher
 
 - (void)fetchImageForSuggestion:
             (ContentSuggestionIdentifier*)suggestionIdentifier
-                       callback:(void (^)(const gfx::Image&))callback {
+                       callback:(void (^)(UIImage*))callback {
   self.contentService->FetchSuggestionImage(
       SuggestionIDForSectionID(
           [self categoryWrapperForSectionInfo:suggestionIdentifier.sectionInfo],
           suggestionIdentifier.IDInSection),
-      base::BindBlockArc(callback));
+      base::BindBlockArc(^(const gfx::Image& image) {
+        if (image.IsEmpty() || !callback) {
+          return;
+        }
+
+        callback([image.ToUIImage() copy]);
+      }));
 }
 
 #pragma mark - Private
 
 - (void)addSuggestions:
             (const std::vector<ntp_snippets::ContentSuggestion>&)suggestions
           fromCategory:(ntp_snippets::Category&)category
                toArray:(NSMutableArray<ContentSuggestion*>*)contentArray {
   if (!ntp_snippets::IsCategoryStatusAvailable(
           self.contentService->GetCategoryStatus(category))) {
@@ skipping 57 matching lines @@
         [NSMutableArray array];
     ntp_snippets::Category category = suggestions[0].id().category();
     [self addSuggestions:suggestions
             fromCategory:category
                  toArray:contentSuggestions];
     callback(contentSuggestions);
   }
 }
 
 @end