Deprecate NonThreadSafe in components/sync in favor of SequenceChecker.

components/sync/base/weak_handle.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef COMPONENTS_SYNC_BASE_WEAK_HANDLE_H_
 #define COMPONENTS_SYNC_BASE_WEAK_HANDLE_H_
 
 #include <cstddef>
 #include <utility>
 
@@ skipping 29 matching lines @@
 //   }
 //
 //   void OnIOError(IOError err) {
 //     foo_.Call(FROM_HERE, &Foo::OnIOError, err);
 //   }
 //
 //  private:
 //   const WeakHandle<Foo> foo_;
 // };
 //
-// class Foo : public SupportsWeakPtr<Foo>, public NonThreadSafe {
+// class Foo : public SupportsWeakPtr<Foo> {
 //  public:
 //   Foo() {
 //     SpawnFooIOWorkerOnIOThread(base::MakeWeakHandle(AsWeakPtr()));
 //   }
 //
 //   /* Will always be called on the correct thread, and only if this
 //      object hasn't been destroyed. */
 //   void OnIOStart() { DCHECK(CalledOnValidThread(); ... }
 //   void OnIOEvent(IOEvent e) { DCHECK(CalledOnValidThread(); ... }
 //   void OnIOError(IOError err) { DCHECK(CalledOnValidThread(); ... }
+//
+//  private:
+//   SEQUENCE_CHECKER(sequence_checker_);
 // };
 
 namespace tracked_objects {
 class Location;
 }  // namespace tracked_objects
 
 namespace syncer {
 
 template <typename T>
 class WeakHandle;
@@ skipping 123 matching lines @@
 
 // Makes a WeakHandle from a WeakPtr.
 template <typename T>
 WeakHandle<T> MakeWeakHandle(const base::WeakPtr<T>& ptr) {
   return WeakHandle<T>(ptr);
 }
 
 }  // namespace syncer
 
 #endif  // COMPONENTS_SYNC_BASE_WEAK_HANDLE_H_