Fix macro redefinition warning on 10.6 bots in mesa code.

R=humper@google.com
Review URL: https://codereview.appspot.com/7063050

git-svn-id: http://skia.googlecode.com/svn/trunk@7086 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp b/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp
index 2f712e3..1b4b7f6 100644
--- a/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp
+++ b/src/gpu/gl/mesa/GrGLCreateMesaInterface.cpp
@@ -11,7 +11,7 @@
 #include "../GrGLUtil.h"
 
 #define GL_GLEXT_PROTOTYPES
-#include <GL/osmesa.h>
+#include "osmesa_wrapper.h"
 
 #define GR_GL_GET_PROC(F) interface->f ## F = (GrGL ## F ## Proc) \
         OSMesaGetProcAddress("gl" #F);