Clone of chromium aad1ce808763f59c7a3753e08f1500a104ecc6fd refs/remotes/origin/HEAD
diff --git a/base/synchronization/cancellation_flag.cc b/base/synchronization/cancellation_flag.cc
new file mode 100644
index 0000000..ad3b551
--- /dev/null
+++ b/base/synchronization/cancellation_flag.cc
@@ -0,0 +1,22 @@
+// Copyright (c) 2011 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.
+
+#include "base/synchronization/cancellation_flag.h"
+
+#include "base/logging.h"
+
+namespace base {
+
+void CancellationFlag::Set() {
+#if !defined(NDEBUG)
+ DCHECK_EQ(set_on_, PlatformThread::CurrentId());
+#endif
+ base::subtle::Release_Store(&flag_, 1);
+}
+
+bool CancellationFlag::IsSet() const {
+ return base::subtle::Acquire_Load(&flag_) != 0;
+}
+
+} // namespace base
