Make GrGLDefines.h be a private header

Review URL: http://codereview.appspot.com/6198048/



git-svn-id: http://skia.googlecode.com/svn/trunk@3851 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/GrGLCreateNullInterface.cpp b/src/gpu/gl/GrGLCreateNullInterface.cpp
index 1a01d92..0a27a06 100644
--- a/src/gpu/gl/GrGLCreateNullInterface.cpp
+++ b/src/gpu/gl/GrGLCreateNullInterface.cpp
@@ -9,6 +9,7 @@
 
 #include "gl/GrGLInterface.h"
 #include "../GrTDArray.h"
+#include "GrGLDefines.h"
 
 GrGLvoid GR_GL_FUNCTION_TYPE nullGLActiveTexture(GrGLenum texture) {}
 GrGLvoid GR_GL_FUNCTION_TYPE nullGLAttachShader(GrGLuint program, GrGLuint shader) {}