Support sync mojo IPCs to and from bindings running on a sequence.

mojo/public/cpp/bindings/sync_handle_watcher.h

 // Copyright 2016 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 MOJO_PUBLIC_CPP_BINDINGS_SYNC_HANDLE_WATCHER_H_
 #define MOJO_PUBLIC_CPP_BINDINGS_SYNC_HANDLE_WATCHER_H_
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/thread_checker.h"
+#include "base/sequence_checker.h"
 #include "mojo/public/cpp/bindings/bindings_export.h"
 #include "mojo/public/cpp/bindings/sync_handle_registry.h"
 #include "mojo/public/cpp/system/core.h"
 
 namespace mojo {
 
 // SyncHandleWatcher supports watching a handle synchronously. It also supports
 // registering the handle with a thread-local storage (SyncHandleRegistry), so
 // that when other SyncHandleWatcher instances on the same thread perform sync
 // handle watching, this handle will be watched together.
@@ skipping 37 matching lines @@
 
   // Whether |handle_| has been registered with SyncHandleRegistry.
   bool registered_;
   // If non-zero, |handle_| should be registered with SyncHandleRegistry.
   size_t register_request_count_;
 
   scoped_refptr<SyncHandleRegistry> registry_;
 
   scoped_refptr<base::RefCountedData<bool>> destroyed_;
 
-  base::ThreadChecker thread_checker_;
+  base::SequenceChecker sequence_checker_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncHandleWatcher);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_PUBLIC_CPP_BINDINGS_SYNC_HANDLE_WATCHER_H_