Adds a Fetch() method to the ContentSuggestionService which asks any provider to provide more conte…

components/ntp_snippets/content_suggestions_service_unittest.cc

Index: components/ntp_snippets/content_suggestions_service_unittest.cc
diff --git a/components/ntp_snippets/content_suggestions_service_unittest.cc b/components/ntp_snippets/content_suggestions_service_unittest.cc
index 99d7a3fd0259b478e397167124398b0371f48247..978d01b3ae409035dc4197a69a192d01126a7188 100644
--- a/components/ntp_snippets/content_suggestions_service_unittest.cc
+++ b/components/ntp_snippets/content_suggestions_service_unittest.cc
@@ -88,6 +88,10 @@ class MockProvider : public ContentSuggestionsProvider {
                void(base::Time begin,
                     base::Time end,
                     const base::Callback<bool(const GURL& url)>& filter));
+  MOCK_METHOD3(Fetch,
+               void(const Category&,
+                    const std::set<std::string>&,
+                    FetchingCallback));
   MOCK_METHOD1(ClearCachedSuggestions, void(Category category));
   MOCK_METHOD2(GetDismissedSuggestionsForDebugging,
                void(Category category,
@@ -575,6 +579,16 @@ TEST_F(ContentSuggestionsServiceTest, ShouldForwardClearHistory) {
   service()->ClearHistory(begin, end, filter);
 }
 
+TEST_F(ContentSuggestionsServiceTest, ShouldForwardFetch) {
+  Category category = FromKnownCategory(KnownCategories::ARTICLES);
+  std::set<std::string> known_suggestions;
+  MockProvider* provider = RegisterProvider(category);
+  provider->FireCategoryStatusChangedWithCurrentStatus(category);
+  EXPECT_CALL(*provider, Fetch(category, known_suggestions, _));
+  service()->Fetch(category, known_suggestions,
+                   ContentSuggestionsService::FetchingCallback());
+}
+
 TEST_F(ContentSuggestionsServiceTest, DismissAndRestoreCategory) {
   // Register a category with one suggestion.
   Category category = FromKnownCategory(KnownCategories::ARTICLES);