Change HistoryService::QueryURL to use CancelableTaskTracker

chrome/browser/extensions/api/history/history_api.cc

Index: chrome/browser/extensions/api/history/history_api.cc
diff --git a/chrome/browser/extensions/api/history/history_api.cc b/chrome/browser/extensions/api/history/history_api.cc
index bf0608865f676d5df3dc43837696378e3722452e..a454ce2dbba8b816c157eb3c43a2ee60bc9df981 100644
--- a/chrome/browser/extensions/api/history/history_api.cc
+++ b/chrome/browser/extensions/api/history/history_api.cc
@@ -301,22 +301,20 @@ bool HistoryGetVisitsFunction::RunAsyncImpl() {
       GetProfile(), Profile::EXPLICIT_ACCESS);
   hs->QueryURL(url,
                true,  // Retrieve full history of a URL.
-               &cancelable_consumer_,
                base::Bind(&HistoryGetVisitsFunction::QueryComplete,
-                          base::Unretained(this)));
-
+                          base::Unretained(this)),
+               &task_tracker_);
   return true;
 }
 
 void HistoryGetVisitsFunction::QueryComplete(
-    HistoryService::Handle request_service,
     bool success,
-    const history::URLRow* url_row,
-    history::VisitVector* visits) {
+    const history::URLRow& url_row,
+    const history::VisitVector& visits) {
   VisitItemList visit_item_vec;
-  if (visits && !visits->empty()) {
-    for (history::VisitVector::iterator iterator = visits->begin();
-         iterator != visits->end();
+  if (success && !visits.empty()) {

[blundell, 2014/06/11 11:08:40]

The value of success is the same as the value of visits being non-NULL (in the
old version of the callback)?

[sdefresne, 2014/06/11 16:46:25]

The QueryURL callback description says "If success is false, neither the row nor
the vector will be valid." So the code incorrectly used the visits parameter
previously. When success is false, the pointer was non-NULL but the vector was
empty.

+    for (history::VisitVector::const_iterator iterator = visits.begin();
+         iterator != visits.end();
          ++iterator) {
       visit_item_vec.push_back(make_linked_ptr(
           GetVisitItem(*iterator).release()));