Bug 1056947 - Don't enable GLFeature::draw_buffers (and therefore WEBGL_draw_buffers) on GLES3 r=jgilbert

--HG--
extra : rebase_source : b2ba97bf610bc414ab744ab08d788b740d518578

gfx/gl/GLContextFeatures.cpp

@@ -87,7 +87,7 @@ static const FeatureInfo sFeatureInfoArr[] = {
     {
         "draw_buffers",
         200, // OpenGL version
-        300, // OpenGL ES version
+        0, // Only enable when we have the extension on ES, bug 1056947
         GLContext::Extension_None,
         {
             GLContext::ARB_draw_buffers,