Reverting 27389.

chrome/browser/visitedlink_master.cc

Index: chrome/browser/visitedlink_master.cc
===================================================================
--- chrome/browser/visitedlink_master.cc	(revision 27591)
+++ chrome/browser/visitedlink_master.cc	(working copy)
@@ -165,8 +165,9 @@
 // Sometimes, the master will be deleted before the rebuild is complete, in
 // which case it notifies the builder via DisownMaster(). The builder will
 // delete itself once rebuilding is complete, and not execute any callback.
-class VisitedLinkMaster::TableBuilder : public HistoryService::URLEnumerator,
-                                        public base::RefCounted<TableBuilder> {
+class VisitedLinkMaster::TableBuilder :
+    public HistoryService::URLEnumerator,
+    public base::RefCountedThreadSafe<TableBuilder> {
  public:
   TableBuilder(VisitedLinkMaster* master,
                const uint8 salt[LINK_SALT_LENGTH]);