[mutter] Consider the right CONTEXT_LOST token on OpenGL ES contexts

[Mario Sanchez Prada <msanchez src gnome org>]

commit 229ac9c9dcc9fe8a1462c742ba1776e090bc37a1
Author: Mario Sanchez Prada <mario endlessm com>
Date:   Mon Apr 17 12:27:59 2017 +0100

    Consider the right CONTEXT_LOST token on OpenGL ES contexts
    
    The KHR_robustness extension defined the following token as
    returned by GetError (see spec at [1]):
    
      CONTEXT_LOST  0x0507
    
    As noted in the spec, this token must have a "_KHR" suffix in
    an OpenGL ES context, which is not being considered here, thus
    making this type of builds fail.
    
    [1] https://www.khronos.org/registry/OpenGL/extensions/KHR/KHR_robustness.txt
    
    https://bugzilla.gnome.org/show_bug.cgi?id=781398

 cogl/cogl/driver/gl/cogl-util-gl-private.h |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/cogl/cogl/driver/gl/cogl-util-gl-private.h b/cogl/cogl/driver/gl/cogl-util-gl-private.h
index 1407e0f..74db6ee 100644
--- a/cogl/cogl/driver/gl/cogl-util-gl-private.h
+++ b/cogl/cogl/driver/gl/cogl-util-gl-private.h
@@ -37,6 +37,11 @@
 #include "cogl-gl-header.h"
 #include "cogl-texture.h"
 
+/* In OpenGL ES context, GL_CONTEXT_LOST has a _KHR prefix */
+#ifndef GL_CONTEXT_LOST
+#define GL_CONTEXT_LOST GL_CONTEXT_LOST_KHR
+#endif
+
 #ifdef COGL_GL_DEBUG
 
 const char *