Deprecate NonThreadSafe in components/invalidation in favor of SequenceChecker.

components/invalidation/impl/registration_manager.h

Index: components/invalidation/impl/registration_manager.h
diff --git a/components/invalidation/impl/registration_manager.h b/components/invalidation/impl/registration_manager.h
index d608bd8c142a56ed17970fcf48cc59d9e6b76138..ebb6ec57ce2daa56ec22aae88c51613e5f6d537b 100644
--- a/components/invalidation/impl/registration_manager.h
+++ b/components/invalidation/impl/registration_manager.h
@@ -12,7 +12,7 @@
 #include <memory>
 
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 // For invalidation::InvalidationListener::RegistrationState.
@@ -33,7 +33,7 @@ using ::invalidation::InvalidationListener;
 // implementations include the syncer thread (both versions) and XMPP
 // retries.  The most sophisticated one is URLRequestThrottler; making
 // that generic should work for everyone.
-class INVALIDATION_EXPORT RegistrationManager : public base::NonThreadSafe {
+class INVALIDATION_EXPORT RegistrationManager {
  public:
   // Constants for exponential backoff (used by tests).
   static const int kInitialRegistrationDelaySeconds;
@@ -179,6 +179,8 @@ class INVALIDATION_EXPORT RegistrationManager : public base::NonThreadSafe {
   // Weak pointer.
   invalidation::InvalidationClient* invalidation_client_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(RegistrationManager);
 };