Deprecate NonThreadSafe in components/sync in favor of SequenceChecker.

components/sync/engine_impl/sync_scheduler_impl.h

Index: components/sync/engine_impl/sync_scheduler_impl.h
diff --git a/components/sync/engine_impl/sync_scheduler_impl.h b/components/sync/engine_impl/sync_scheduler_impl.h
index 92572f8f64bc8bdf81d4be37f31aceb4486770d5..d83b03865d864181a51065ed63d433f1c55322bf 100644
--- a/components/sync/engine_impl/sync_scheduler_impl.h
+++ b/components/sync/engine_impl/sync_scheduler_impl.h
@@ -15,7 +15,7 @@
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "components/sync/engine/polling_constants.h"
@@ -32,7 +32,7 @@ namespace syncer {
 class BackoffDelayProvider;
 struct ModelNeutralState;
 
-class SyncSchedulerImpl : public SyncScheduler, public base::NonThreadSafe {
+class SyncSchedulerImpl : public SyncScheduler {
  public:
   // |name| is a display string to identify the syncer thread.  Takes
   // |ownership of |syncer| and |delay_provider|.
@@ -294,6 +294,8 @@ class SyncSchedulerImpl : public SyncScheduler, public base::NonThreadSafe {
   // Dictates if the scheduler should wait for authentication to happen or not.
   bool ignore_auth_credentials_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   base::WeakPtrFactory<SyncSchedulerImpl> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncSchedulerImpl);