Advertise robustness extension strings.

Trac #18607
Signed-off-by: Daniel Koch
Author: Nicolas Capens

git-svn-id: https://angleproject.googlecode.com/svn/trunk@850 736b8ea6-26fd-11df-bfd4-992fa37f6226
diff --git a/src/libGLESv2/Context.cpp b/src/libGLESv2/Context.cpp
index 936c9ab..cef8bad 100644
--- a/src/libGLESv2/Context.cpp
+++ b/src/libGLESv2/Context.cpp
@@ -3420,6 +3420,7 @@
 
     // Multi-vendor (EXT) extensions
     mExtensionString += "GL_EXT_read_format_bgra ";
+    mExtensionString += "GL_EXT_robustness ";
 
     if (supportsDXT1Textures())
     {