Ntp: show AllDismissedItem when all sections have been dismissed.

components/ntp_snippets/content_suggestions_service.h

Index: components/ntp_snippets/content_suggestions_service.h
diff --git a/components/ntp_snippets/content_suggestions_service.h b/components/ntp_snippets/content_suggestions_service.h
index 987a9fb4accd0cf0d623b1b970cb0195a24be638..19e87fa27dd6ff663a87c155e8d2839e2d1d9643 100644
--- a/components/ntp_snippets/content_suggestions_service.h
+++ b/components/ntp_snippets/content_suggestions_service.h
@@ -125,6 +125,10 @@ class ContentSuggestionsService : public KeyedService,
   // This will not trigger an update through the observers.
   void DismissCategory(Category category);
 
+  // Restores all dismissed categories.
+  // This will not trigger an update through the observers.
+  void RestoreDismissedCategories();
+
   // Observer accessors.
   void AddObserver(Observer* observer);
   void RemoveObserver(Observer* observer);
@@ -242,6 +246,11 @@ class ContentSuggestionsService : public KeyedService,
   // |providers_by_category_|.
   std::vector<Category> categories_;
 
+  // All dismissed categories and their providers. These may be restored by
+  // RestoreDismissedCategories().
+  std::map<Category, ContentSuggestionsProvider*, Category::CompareByID>
+      dismissed_providers_by_category_;

[Marc Treib, 2016/10/11 07:35:58]

nit: Maybe move this next to provider_by_category_?

[Michael van Ouwerkerk, 2016/10/11 12:04:16]

Done.

+
   // All current suggestions grouped by category. This contains an entry for
   // every category in |categories_| whose status is an available status. It may
   // contain an empty vector if the category is available but empty (or still