Change HistoryService::QueryURL to use CancelableTaskTracker

chrome/browser/custom_home_pages_table_model.h

Index: chrome/browser/custom_home_pages_table_model.h
diff --git a/chrome/browser/custom_home_pages_table_model.h b/chrome/browser/custom_home_pages_table_model.h
index 64a8b82362d0de30d5e4f5f9a21a36b808a79bab..be6e7ec3c1626ecda343d7049e9978e3f16d62b0 100644
--- a/chrome/browser/custom_home_pages_table_model.h
+++ b/chrome/browser/custom_home_pages_table_model.h
@@ -9,11 +9,17 @@
 #include <vector>
 
 #include "base/compiler_specific.h"
-#include "chrome/browser/history/history_service.h"
+#include "base/task/cancelable_task_tracker.h"
+#include "chrome/browser/history/history_types.h"
 #include "ui/base/models/table_model.h"
 
 class GURL;
 class Profile;
+class HistoryService;
+
+namespace history {
+class URLRow;
+}
 
 namespace ui {
 class TableModelObserver;
@@ -63,17 +69,11 @@ class CustomHomePagesTableModel : public ui::TableModel {
   void LoadTitle(Entry* entry);
 
   // Callback from history service. Updates the title of the Entry whose
-  // |title_handle| matches |handle| and notifies the observer of the change.
-  void OnGotTitle(HistoryService::Handle handle,
+  // |url| matches |entry_url| and notifies the observer of the change.
+  void OnGotTitle(const GURL& entry_url,
                   bool found_url,
-                  const history::URLRow* row,
-                  history::VisitVector* visits);
-
-  // Returns the entry whose |member| matches |handle| and sets |entry_index| to
-  // the index of the entry.
-  Entry* GetEntryByLoadHandle(CancelableRequestProvider::Handle Entry::* member,
-                              CancelableRequestProvider::Handle handle,
-                              int* entry_index);
+                  const history::URLRow& row,
+                  const history::VisitVector& visits);
 
   // Returns the URL for a particular row, formatted for display to the user.
   base::string16 FormattedURL(int row) const;
@@ -87,7 +87,7 @@ class CustomHomePagesTableModel : public ui::TableModel {
   ui::TableModelObserver* observer_;
 
   // Used in loading titles.
-  CancelableRequestConsumer history_query_consumer_;
+  base::CancelableTaskTracker task_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(CustomHomePagesTableModel);
 };