Get Suggestions image only if it is not empty

ios/chrome/browser/ui/content_suggestions/content_suggestions_collection_updater.mm

 // Copyright 2016 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/ui/content_suggestions/content_suggestions_collection_updater.h"
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
 #include "base/time/time.h"
 #import "ios/chrome/browser/ui/collection_view/collection_view_controller.h"
@@ skipping 135 matching lines @@
 
 #pragma mark - ContentSuggestionsArticleItemDelegate
 
 - (void)loadImageForArticleItem:(ContentSuggestionsArticleItem*)articleItem {
   NSInteger sectionIdentifier =
       SectionIdentifierForInfo(articleItem.suggestionIdentifier.sectionInfo);
 
   __weak ContentSuggestionsCollectionUpdater* weakSelf = self;
   __weak ContentSuggestionsArticleItem* weakArticle = articleItem;
   void (^imageFetchedCallback)(const gfx::Image&) = ^(const gfx::Image& image) {
+    if (image.IsEmpty()) {
+      return;
+    }
+
     ContentSuggestionsCollectionUpdater* strongSelf = weakSelf;
     ContentSuggestionsArticleItem* strongArticle = weakArticle;
     if (!strongSelf || !strongArticle) {
       return;
     }
 
-    strongArticle.imageBeingFetched = NO;
     strongArticle.image = image.CopyUIImage();
     [strongSelf.collectionViewController
         reconfigureCellsForItems:@[ strongArticle ]
          inSectionWithIdentifier:sectionIdentifier];
   };
 
-  articleItem.imageBeingFetched = YES;
-
   [self.dataSource.imageFetcher
       fetchImageForSuggestion:articleItem.suggestionIdentifier
                      callback:imageFetchedCallback];
 }
 
 #pragma mark - Private methods
 
 - (void)reloadData {
   [self resetModels];
   CollectionViewModel* model =
@@ skipping 40 matching lines @@
   }
   return sectionIdentifier;
 }
 
 - (void)resetModels {
   [self.collectionViewController loadModel];
   self.sectionInfoBySectionIdentifier = [[NSMutableDictionary alloc] init];
 }
 
 @end