Port HistoryService::GetVisibleVisitCountToHost to CancelableTaskTracker

chrome/browser/history/history_backend.cc

Index: chrome/browser/history/history_backend.cc
diff --git a/chrome/browser/history/history_backend.cc b/chrome/browser/history/history_backend.cc
index a2437b1f160071d7cac23d2565e0338616534f22..805598ceace6b3ff44bffc66ae3a33b0c9beaded 100644
--- a/chrome/browser/history/history_backend.cc
+++ b/chrome/browser/history/history_backend.cc
@@ -1277,15 +1277,12 @@ void HistoryBackend::QueryRedirectsTo(const GURL& to_url,
 }
 
 void HistoryBackend::GetVisibleVisitCountToHost(
-    scoped_refptr<GetVisibleVisitCountToHostRequest> request,
-    const GURL& url) {
-  if (request->canceled())
-    return;
-  int count = 0;
-  Time first_visit;
-  const bool success = db_.get() &&
-      db_->GetVisibleVisitCountToHost(url, &count, &first_visit);
-  request->ForwardResult(request->handle(), success, count, first_visit);
+    const GURL& url,
+    VisibleVisitCountToHostResult* result) {
+  result->count = 0;
+  result->success = db_.get() &&
+                    db_->GetVisibleVisitCountToHost(
+                        url, &result->count, &result->first_visit);
 }
 
 void HistoryBackend::QueryMostVisitedURLs(int result_count,