Add CategoryInfo for meta information of content suggestions Categories

components/ntp_snippets/content_suggestions_service.cc

Index: components/ntp_snippets/content_suggestions_service.cc
diff --git a/components/ntp_snippets/content_suggestions_service.cc b/components/ntp_snippets/content_suggestions_service.cc
index 1b9ecb839cb7d4cedb90f40dc88d6be2ce605fd9..3e52d1311bcece1757be9d202ca6d40c0d57c69a 100644
--- a/components/ntp_snippets/content_suggestions_service.cc
+++ b/components/ntp_snippets/content_suggestions_service.cc
@@ -48,6 +48,15 @@ CategoryStatus ContentSuggestionsService::GetCategoryStatus(
   return iterator->second->GetCategoryStatus(category);
 }
 
+CategoryInfo ContentSuggestionsService::GetCategoryInfo(
+    Category category) const {
+  auto iterator = providers_by_category_.find(category);
+  if (iterator == providers_by_category_.end())
+    return CategoryInfo(base::string16());

[PEConn, 2016/08/04 12:08:39]

What does this represent - an empty category or an invalid category? What will
happen when this case occurs - do we just pass the empty title forward?

If it's an invalid category can we have some sort of CategoryInfo.Valid method?

[Philipp Keck, 2016/08/04 14:17:43]

We're discussing the possibility of returning an Optional<CategoryInfo>. See the
discussion there.

+
+  return iterator->second->GetCategoryInfo(category);
+}
+
 const std::vector<ContentSuggestion>&
 ContentSuggestionsService::GetSuggestionsForCategory(Category category) const {
   auto iterator = suggestions_by_category_.find(category);