[NTP] Fix article suggestion clicks contributing to Most Visited tiles

components/history/core/browser/history_backend_unittest.cc

Index: components/history/core/browser/history_backend_unittest.cc
diff --git a/components/history/core/browser/history_backend_unittest.cc b/components/history/core/browser/history_backend_unittest.cc
index 8f4b22f2d645616981efdf0bb5818d9c72e6d6d8..3de663e0a7101985d82a58b9aa90ad7f0c140683 100644
--- a/components/history/core/browser/history_backend_unittest.cc
+++ b/components/history/core/browser/history_backend_unittest.cc
@@ -3806,4 +3806,37 @@ TEST_F(InMemoryHistoryBackendTest, OnURLsDeletedWithSearchTerms) {
   EXPECT_FALSE(mem_backend_->db()->GetKeywordSearchTermRow(row2.id(), NULL));
 }
 
+TEST_F(HistoryBackendTest, QueryMostVisitedURLs) {
+  const GURL kChromeSearchContentSuggestionsReferrer(
+      "https://www.googleapis.com/auth/chrome-content-suggestions");
+
+  ASSERT_TRUE(backend_.get());
+
+  // Pairs from page transitions to referrer URLs.
+  std::vector<std::pair<ui::PageTransition, GURL>> pages;
+  pages.emplace_back(ui::PAGE_TRANSITION_AUTO_BOOKMARK, GURL());  // good.
+  pages.emplace_back(ui::PAGE_TRANSITION_AUTO_BOOKMARK,
+                     kChromeSearchContentSuggestionsReferrer);  // bad.
+  pages.emplace_back(ui::PAGE_TRANSITION_LINK, GURL());         // bad.
+  pages.emplace_back(ui::PAGE_TRANSITION_TYPED, GURL());        // good.
+
+  for (size_t i = 0; i < pages.size(); ++i) {
+    HistoryAddPageArgs args;
+    args.url = GURL("http://example" + base::SizeTToString(i + 1) + ".com");
+    args.time = base::Time::Now() - base::TimeDelta::FromDays(i + 1);
+    args.transition = pages[i].first;
+    args.referrer = pages[i].second;
+    backend_->AddPage(args);
+  }
+
+  MostVisitedURLList most_visited;
+  backend_->QueryMostVisitedURLs(100, 100, &most_visited);
+
+  const base::string16 kSomeTitle;  // Ignored by equality operator.
+  EXPECT_THAT(
+      most_visited,
+      ElementsAre(MostVisitedURL(GURL("http://example1.com"), kSomeTitle),
+                  MostVisitedURL(GURL("http://example4.com"), kSomeTitle)));
+}
+
 }  // namespace history