Move the Dispatcher::EntrypointClass enum out of Dispatcher to its own file.

mojo/edk/system/entrypoint_class.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_EDK_SYSTEM_ENTRYPOINT_CLASS_H_
+#define MOJO_EDK_SYSTEM_ENTRYPOINT_CLASS_H_
+
+namespace mojo {
+namespace system {
+
+// Classes of "entrypoints"/"syscalls": Each dispatcher should support entire
+// classes of methods (and if they don't support a given class, they should
+// return |MOJO_RESULT_INVALID_ARGUMENT| for all the methods in that class).
+// Warning: A dispatcher method may be called even if the dispatcher's
+// |SupportsEntrypointClass()| indicates that the method's class is not
+// supported.
+enum class EntrypointClass {
+  // |Dispatcher::ReadMessage()|, |Dispatcher::WriteMessage()|:
+  MESSAGE_PIPE,
+
+  // |Dispatcher::SetDataPipeProducerOptions()|,
+  // |Dispatcher::GetDataPipeProducerOptions()|,
+  // |Dispatcher::WriteData()|, |Dispatcher::BeginWriteData()|,
+  // |Dispatcher::EndWriteData()|:
+  DATA_PIPE_PRODUCER,
+
+  // |Dispatcher::SetDataPipeConsumerOptions()|,
+  // |Dispatcher::GetDataPipeConsumerOptions()|, |Dispatcher::ReadData()|,
+  // |Dispatcher::BeginReadData()|, |Dispatcher::EndReadData()|:
+  DATA_PIPE_CONSUMER,
+
+  // |Dispatcher::DuplicateBufferHandle()|,
+  // |Dispatcher::GetBufferInformation()|, |Dispatcher::MapBuffer()|:
+  BUFFER,
+};
+
+}  // namespace system
+}  // namespace mojo
+
+#endif  // MOJO_EDK_SYSTEM_ENTRYPOINT_CLASS_H_