Revert of Mojo: Eliminate duplicate C API symbols

mojo/edk/embedder/entrypoints.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_EMBEDDER_ENTRYPOINTS_H_
-#define MOJO_EDK_EMBEDDER_ENTRYPOINTS_H_
-
-#include "mojo/edk/system/system_impl_export.h"
-#include "mojo/public/c/system/thunks.h"
-
-namespace mojo {
-namespace edk {
-
-// Creates a MojoSystemThunks struct populated with the EDK's implementation of
-// each function. This may be used by embedders to populate thunks for
-// application loading.
-MOJO_SYSTEM_IMPL_EXPORT MojoSystemThunks MakeSystemThunks();
-
-}  // namespace edk
-}  // namespace mojo
-
-#endif  // MOJO_EDK_EMBEDDER_ENTRYPOINTS_H_