Move more Mojo bindings helpers out of internal namespace

mojo/public/cpp/bindings/lib/pipe_control_message_proxy.h

-// Copyright 2015 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_LIB_PIPE_CONTROL_MESSAGE_PROXY_H_
-#define MOJO_PUBLIC_CPP_BINDINGS_LIB_PIPE_CONTROL_MESSAGE_PROXY_H_
-
-#include "base/macros.h"
-#include "mojo/public/cpp/bindings/interface_id.h"
-#include "mojo/public/cpp/bindings/lib/serialization_context.h"
-
-namespace mojo {
-
-class MessageReceiver;
-
-namespace internal {
-
-// Proxy for request messages defined in pipe_control_messages.mojom.
-class PipeControlMessageProxy {
- public:
-  // Doesn't take ownership of |receiver|. It must outlive this object.
-  explicit PipeControlMessageProxy(MessageReceiver* receiver);
-
-  void NotifyPeerEndpointClosed(InterfaceId id);
-  void NotifyEndpointClosedBeforeSent(InterfaceId id);
-
- private:
-  // Not owned.
-  MessageReceiver* receiver_;
-  SerializationContext context_;
-
-  DISALLOW_COPY_AND_ASSIGN(PipeControlMessageProxy);
-};
-
-}  // namespace internal
-}  // namespace mojo
-
-#endif  // MOJO_PUBLIC_CPP_BINDINGS_LIB_PIPE_CONTROL_MESSAGE_PROXY_H_