More explicit thread checking in SafeBrowsingDatabase.

chrome/browser/safe_browsing/safe_browsing_database.h

Index: chrome/browser/safe_browsing/safe_browsing_database.h
diff --git a/chrome/browser/safe_browsing/safe_browsing_database.h b/chrome/browser/safe_browsing/safe_browsing_database.h
index c011b9bfc7a526e8c2df0e43ddc6e1c3536d04d4..7de801b65658a6ebef56139c1278d540633fa7f2 100644
--- a/chrome/browser/safe_browsing/safe_browsing_database.h
+++ b/chrome/browser/safe_browsing/safe_browsing_database.h
@@ -16,13 +16,10 @@
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
+#include "base/threading/thread_checker.h"
 #include "base/time/time.h"
 #include "chrome/browser/safe_browsing/safe_browsing_store.h"
 
-namespace base {
-class MessageLoop;
-}
-
 namespace safe_browsing {
 class PrefixSet;
 }
@@ -469,8 +466,8 @@ class SafeBrowsingDatabaseNew : public SafeBrowsingDatabase {
   void UpdateIpBlacklistStore();
 
   // Used to verify that various calls are made from the thread the
-  // object was created on.
-  base::MessageLoop* creation_loop_;
+  // object was created on (i.e., the safe_browsing_thread).
+  base::ThreadChecker thread_checker_;
 
   // The base filename passed to Init(), used to generate the store and prefix
   // set filenames used to store data on disk.