[cros] RlzValueStore made protected by a cross-process lock and not persisted over browser lifetime…

chrome/browser/rlz/rlz.h

Index: chrome/browser/rlz/rlz.h
diff --git a/chrome/browser/rlz/rlz.h b/chrome/browser/rlz/rlz.h
index 6a1d3c2310ff9dd3a32aaafb31c0753796ca7be8..3d0f97e6fbb6f5957e380d243f418ce16d1620c3 100644
--- a/chrome/browser/rlz/rlz.h
+++ b/chrome/browser/rlz/rlz.h
@@ -15,11 +15,13 @@
 #include "base/basictypes.h"
 #include "base/memory/singleton.h"
 #include "base/string16.h"
-#include "base/threading/thread.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 #include "rlz/lib/rlz_lib.h"
 
+namespace base {
+class SequencedTaskRunner;
+}
 namespace net {
 class URLRequestContextGetter;
 }
@@ -169,9 +171,6 @@ class RLZTracker : public content::NotificationObserver {
   bool is_google_homepage_;
   bool is_google_in_startpages_;
 
-  // Dedicated RLZ thread for accessing RlzValueStore and doing I/O.
-  base::Thread rlz_thread_;
-
   // Sequenced task runner used to post blocking tasks that access
   // RlzValueStore.
   base::SequencedTaskRunner* blocking_task_runner_;