Replace deprecated base::NonThreadSafe in chrome/service in favor of SequenceChecker.

chrome/service/cloud_print/cloud_print_token_store.h

Index: chrome/service/cloud_print/cloud_print_token_store.h
diff --git a/chrome/service/cloud_print/cloud_print_token_store.h b/chrome/service/cloud_print/cloud_print_token_store.h
index 767619b51e7f722a6e1b81d14aa58f3a35389c3b..b61ed9eeb83947a0f0daa0d7a46a45340c44a335 100644
--- a/chrome/service/cloud_print/cloud_print_token_store.h
+++ b/chrome/service/cloud_print/cloud_print_token_store.h
@@ -8,14 +8,14 @@
 #include <string>
 #include "base/logging.h"
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 
 // This class serves as the single repository for cloud print auth tokens. This
 // is only used within the CloudPrintProxyCoreThread.
 
 namespace cloud_print {
 
-class CloudPrintTokenStore : public base::NonThreadSafe {
+class CloudPrintTokenStore {
  public:
   // Returns the CloudPrintTokenStore instance for this thread. Will be NULL
   // if no instance was created in this thread before.
@@ -26,13 +26,15 @@ class CloudPrintTokenStore : public base::NonThreadSafe {
 
   void SetToken(const std::string& token);
   std::string token() const {
-    DCHECK(CalledOnValidThread());
+    DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
     return token_;
   }
 
  private:
   std::string token_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(CloudPrintTokenStore);
 };