Deprecate NonThreadSafe in rlz in favor of SequenceChecker.

rlz/chromeos/lib/rlz_value_store_chromeos.h

Index: rlz/chromeos/lib/rlz_value_store_chromeos.h
diff --git a/rlz/chromeos/lib/rlz_value_store_chromeos.h b/rlz/chromeos/lib/rlz_value_store_chromeos.h
index cae01ba367da91b48658bc7e1cd95bf8a26f2aee..7222a782b1954cf8b8d32c80dfb0bb9379e61be4 100644
--- a/rlz/chromeos/lib/rlz_value_store_chromeos.h
+++ b/rlz/chromeos/lib/rlz_value_store_chromeos.h
@@ -12,7 +12,7 @@
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "rlz/lib/rlz_value_store.h"
 
 namespace base {
@@ -23,8 +23,7 @@ class Value;
 namespace rlz_lib {
 
 // An implementation of RlzValueStore for ChromeOS.
-class RlzValueStoreChromeOS : public RlzValueStore,
-                              public base::NonThreadSafe {
+class RlzValueStoreChromeOS : public RlzValueStore {
  public:
   // Creates new instance and synchronously reads data from file.
   explicit RlzValueStoreChromeOS(const base::FilePath& store_path);
@@ -77,6 +76,8 @@ class RlzValueStoreChromeOS : public RlzValueStore,
 
   bool read_only_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(RlzValueStoreChromeOS);
 };