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

mojo/public/c/include/MGL/mgl.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_MGL_H_
-#define MOJO_PUBLIC_C_GPU_MGL_MGL_H_
+#ifndef MOJO_PUBLIC_C_INCLUDE_MGL_MGL_H_
+#define MOJO_PUBLIC_C_INCLUDE_MGL_MGL_H_
 
+#include <MGL/mgl_types.h>
+#include <mojo/macros.h>
 #include <mojo/system/handle.h>
 #include <stdint.h>
 
-#include "mojo/public/c/gpu/MGL/mgl_types.h"
-
-#ifdef __cplusplus
-extern "C" {
-#endif
+MOJO_BEGIN_EXTERN_C
 
 typedef uint32_t MGLOpenGLAPIVersion;
 
 // OpenGL ES 2.0
 #define MGL_API_VERSION_GLES2 ((MGLOpenGLAPIVersion)1)
 // OpenGL ES 3.0
 #define MGL_API_VERSION_GLES3 ((MGLOpenGLAPIVersion)2)
 // OpenGL ES 3.1
 #define MGL_API_VERSION_GLES31 ((MGLOpenGLAPIVersion)3)
 
@@ skipping 27 matching lines @@
 // if there is none.
 MGLContext MGLGetCurrentContext(void);
 
 // Returns GL function usable in any context that advertise the corresponding
 // extension in their GL_EXTENSIONS string, or null for functions that the
 // implementation does not support. The implementation only advertises GL
 // functions.
 // |name| is the name of the GL function.
 MGLMustCastToProperFunctionPointerType MGLGetProcAddress(const char* name);
 
-#ifdef __cplusplus
-}  // extern "C"
-#endif
+MOJO_END_EXTERN_C
 
-#endif  // MOJO_PUBLIC_C_GPU_MGL_MGL_H_
+#endif  // MOJO_PUBLIC_C_INCLUDE_MGL_MGL_H_