Move mojo/public/c/gpu/* to mojo/public/c/include.

mojo/public/c/include/MGL/mgl_types.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.
 
 // Note: This header should be compilable as C.
 
-#ifndef MOJO_PUBLIC_C_GPU_MGL_TYPES_H_
-#define MOJO_PUBLIC_C_GPU_MGL_TYPES_H_
+#ifndef MOJO_PUBLIC_C_INCLUDE_MGL_TYPES_H_
+#define MOJO_PUBLIC_C_INCLUDE_MGL_TYPES_H_
 
-#ifdef __cplusplus
-extern "C" {
-#endif
+#include <mojo/macros.h>
+
+MOJO_BEGIN_EXTERN_C
 
 typedef struct MGLContextPrivate* MGLContext;
 typedef void (*MGLContextLostCallback)(void* closure);
 typedef void (*MGLSignalSyncPointCallback)(void* closure);
 
 // This is a generic function pointer type, which must be cast to the proper
 // type and calling convention before use.
 typedef void (*MGLMustCastToProperFunctionPointerType)(void);
 
-#ifdef __cplusplus
-}  // extern "C"
-#endif
+MOJO_END_EXTERN_C
 
-#endif  // MOJO_PUBLIC_C_GPU_MGL_TYPES_H_
+#endif  // MOJO_PUBLIC_C_INCLUDE_MGL_TYPES_H_