add support for GL_EXT_debug_marker

This extension is always added to the GL_EXTENSIONS
extension string for the current GL context, regardless
of if it's supported by the h/w driver.

The extension itself will be handled by GLES_trace (eventually),
when GLES_trace is not enabled, it'll result to a no-op.

If the h/w implementation has this extension, we'll call that version
instead of our dummy version.

Change-Id: Ie5dd3387c4d45cd5ed5f03b73bda6045620a96bc
diff --git a/opengl/libs/EGL/egldefs.h b/opengl/libs/EGL/egldefs.h
index 107acd9..ff20957 100644
--- a/opengl/libs/EGL/egldefs.h
+++ b/opengl/libs/EGL/egldefs.h
@@ -58,6 +58,7 @@
 extern gl_hooks_t gHooksNoContext;
 extern pthread_key_t gGLWrapperKey;
 extern "C" void gl_unimplemented();
+extern "C" void gl_noop();
 
 extern char const * const gl_names[];
 extern char const * const egl_names[];