Adding the possibility to build a closure from an ObjectiveC block.

base/mac/bind_objc_block.h

Index: base/mac/bind_objc_block.h
diff --git a/base/mac/bind_objc_block.h b/base/mac/bind_objc_block.h
new file mode 100644
index 0000000000000000000000000000000000000000..5cde9d383872754c83f8846db32c90a2b8de2f44
--- /dev/null
+++ b/base/mac/bind_objc_block.h
@@ -0,0 +1,17 @@
+// Copyright (c) 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 BASE_MAC_BIND_OBJC_BLOCK_H_
+#define BASE_MAC_BIND_OBJC_BLOCK_H_
+
+#include "base/callback_forward.h"
+
+namespace base {
+
+// Construct a closure from an objective-C block.
+base::Closure BindBlock(void(^block)());
+
+}  // namespace base
+
+#endif  // BASE_MAC_BIND_OBJC_BLOCK_H_