Add CategoryInfo for meta information of content suggestions Categories

components/ntp_snippets/content_suggestions_service.cc

 // 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.
 
 #include "components/ntp_snippets/content_suggestions_service.h"
 
 #include <algorithm>
 #include <iterator>
 
 #include "base/bind.h"
@@ skipping 30 matching lines @@
     return CategoryStatus::ALL_SUGGESTIONS_EXPLICITLY_DISABLED;
   }
 
   auto iterator = providers_by_category_.find(category);
   if (iterator == providers_by_category_.end())
     return CategoryStatus::NOT_PROVIDED;
 
   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);
   if (iterator == suggestions_by_category_.end())
     return no_suggestions_;
   return iterator->second;
 }
 
 void ContentSuggestionsService::FetchSuggestionImage(
     const std::string& suggestion_id,
@@ skipping 151 matching lines @@
   return true;
 }
 
 void ContentSuggestionsService::NotifyCategoryStatusChanged(Category category) {
   FOR_EACH_OBSERVER(
       Observer, observers_,
       OnCategoryStatusChanged(category, GetCategoryStatus(category)));
 }
 
 }  // namespace ntp_snippets