Download favicon from server for suggested articles

ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm

Index: ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm
diff --git a/ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm b/ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm
index 19dbe62a4ee352666e252241b74221e5f525a326..12d593fde2523b7238140672ba3038d248e5715e 100644
--- a/ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm
+++ b/ios/chrome/browser/content_suggestions/content_suggestions_mediator.mm
@@ -234,6 +234,26 @@ initWithContentService:(ntp_snippets::ContentSuggestionsService*)contentService
                                              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]);

[lpromero, 2017/04/14 13:19:40]

Is the copy necessary? UIImage is immutable.

[gambard, 2017/04/14 13:28:10]

It is a memory management thing. You can ask stkhapugin for more information.

+    }
+  };
+
+  ntp_snippets::ContentSuggestion::ID identifier =
+      ntp_snippets::ContentSuggestion::ID(
+          [[self categoryWrapperForSectionInfo:suggestion.sectionInfo]
+              category],
+          suggestion.IDInSection);
+  self.contentService->FetchSuggestionFavicon(
+      identifier, 1, kDefaultFaviconSize, base::BindBlockArc(imageCallback));

[lpromero, 2017/04/14 13:19:40]

Optional nit: Can you add something like: "identifier, 1 /*
minimum_size_in_pixel */, kDefaut…"

[gambard, 2017/04/14 13:28:10]

Done.

+}
+
 #pragma mark - ContentSuggestionsServiceObserver
 
 - (void)contentSuggestionsService: