Revert r118525 / Re-land r118240 - the build failure was a flake.

third_party/khronos/GLES2/gl2.h

 #ifndef __gl2_h_
 #define __gl2_h_
 
 /* $Revision: 10602 $ on $Date:: 2010-03-04 22:35:34 -0800 #$ */
 
 #include <GLES2/gl2platform.h>
 
 /*
  * This document is licensed under the SGI Free Software B License Version
  * 2.0. For details, see http://oss.sgi.com/projects/FreeB/ .
@@ skipping 468 matching lines @@
 
 #if defined(GLES2_USE_CPP_BINDINGS)
 #define GLES2_GET_FUN(name) gles2::GetGLContext()->name
 #else
 #define GLES2_GET_FUN(name) GLES2 ## name
 #endif
 
 /*-------------------------------------------------------------------------
  * GL core functions.
  *-----------------------------------------------------------------------*/
-#undef GL_APICALL
-#define GL_APICALL
 #undef GL_APIENTRY
 #define GL_APIENTRY
 
 #define glActiveTexture GLES2_GET_FUN(ActiveTexture)
 #define glAttachShader GLES2_GET_FUN(AttachShader)
 #define glBindAttribLocation GLES2_GET_FUN(BindAttribLocation)
 #define glBindBuffer GLES2_GET_FUN(BindBuffer)
 #define glBindFramebuffer GLES2_GET_FUN(BindFramebuffer)
 #define glBindRenderbuffer GLES2_GET_FUN(BindRenderbuffer)
 #define glBindTexture GLES2_GET_FUN(BindTexture)
@@ skipping 283 matching lines @@
 GL_APICALL void         GL_APIENTRY glViewport (GLint x, GLint y, GLsizei width, GLsizei height);
 
 #if defined(__cplusplus)
 }
 #endif
 
 #endif  // !GLES2_USE_CPP_BINDINGS
 
 #endif /* __gl2_h_ */