Fix for surfaceless implementation

gpu/GLES2/gl2extchromium.h

 // Copyright (c) 2012 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.
 
 // This file contains Chromium-specific GLES2 extensions declarations.
 
 #ifndef GPU_GLES2_GL2EXTCHROMIUM_H_
 #define GPU_GLES2_GL2EXTCHROMIUM_H_
 
 #include <GLES2/gl2.h>
@@ skipping 100 matching lines @@
 #endif
 
 #ifndef GL_IMAGE_MAP_CHROMIUM
 #define GL_IMAGE_MAP_CHROMIUM 0x78F1
 #endif
 
 #ifndef GL_IMAGE_SCANOUT_CHROMIUM
 #define GL_IMAGE_SCANOUT_CHROMIUM 0x78F2
 #endif
 
+#ifndef GL_RGBX8_CHROMIUM
+#define GL_RGBX8_CHROMIUM 0x78F3
+#endif
+
 #ifdef GL_GLEXT_PROTOTYPES
 GL_APICALL GLuint GL_APIENTRY glCreateImageCHROMIUM(GLsizei width,
                                                     GLsizei height,
                                                     GLenum internalformat,
                                                     GLenum usage);
 GL_APICALL void GL_APIENTRY glDestroyImageCHROMIUM(GLuint image_id);
 GL_APICALL void GL_APIENTRY glGetImageParameterivCHROMIUM(
     GLuint image_id, GLenum pname, GLint* params);
 GL_APICALL void* GL_APIENTRY glMapImageCHROMIUM(GLuint image_id);
 GL_APICALL void GL_APIENTRY glUnmapImageCHROMIUM(GLuint image_id);
@@ skipping 600 matching lines @@
 typedef void(GL_APIENTRYP PFNGLMATRIXLOADIDENTITYCHROMIUMPROC)(
     GLenum matrixMode);
 
 #endif /* GL_CHROMIUM_path_rendering */
 
 #ifdef __cplusplus
 }
 #endif
 
 #endif  // GPU_GLES2_GL2EXTCHROMIUM_H_