Allow category["suggestions"] to be absent.

components/ntp_snippets/ntp_snippets_fetcher.cc

Index: components/ntp_snippets/ntp_snippets_fetcher.cc
diff --git a/components/ntp_snippets/ntp_snippets_fetcher.cc b/components/ntp_snippets/ntp_snippets_fetcher.cc
index c0018e7d816ad650ff06f25bdf664b5b64034e2e..8c75df86219eb15f78ed348af1226db462b3a64c 100644
--- a/components/ntp_snippets/ntp_snippets_fetcher.cc
+++ b/components/ntp_snippets/ntp_snippets_fetcher.cc
@@ -540,12 +540,14 @@ bool NTPSnippetsFetcher::JsonToSnippets(const base::Value& parsed,
         const base::ListValue* suggestions = nullptr;

[Marc Treib, 2016/08/25 09:14:02]

nit: Move this down to where it's used.

[sfiera, 2016/08/25 10:24:29]

Done.

         if (!(v->GetAsDictionary(&category_value) &&
               category_value->GetInteger("id", &category_id) &&
-              (category_id > 0) &&
-              category_value->GetList("suggestions", &suggestions))) {
+              (category_id > 0))) {
           return false;
         }
         Category category = category_factory_->FromRemoteCategory(category_id);
         NTPSnippet::PtrVector* articles = &(*snippets)[category];
+        if (!category_value->GetList("suggestions", &suggestions)) {

[tschumann, 2016/08/24 21:35:22]

let's document this case, e.g.,
// Categories are allowed to have empty suggestion lists (which result in an
absent field in JSON).

[Marc Treib, 2016/08/25 09:14:02]

+1 for comment

[sfiera, 2016/08/25 10:24:29]

Done.

+          continue;
+        }
         if (!AddSnippetsFromListValue(
                 /* content_suggestions_api = */ true, *suggestions, articles)) {
           return false;