Add support for GL_DRAW_INDIRECT_BUFFER_BINDING binding point

BUG=angleproject:1595
TEST=dEQP-GLES31.functional.state_query.integer.draw_indirect_buffer_binding*

Change-Id: Ib8f712fdf10411ef0b7b63742d17c3caca99137b
Reviewed-on: https://chromium-review.googlesource.com/416193
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Geoff Lang <geofflang@chromium.org>
Commit-Queue: Geoff Lang <geofflang@chromium.org>
diff --git a/src/libANGLE/ContextState.cpp b/src/libANGLE/ContextState.cpp
index 6e95b2d..144a8f3 100644
--- a/src/libANGLE/ContextState.cpp
+++ b/src/libANGLE/ContextState.cpp
@@ -494,6 +494,7 @@
 
     switch (pname)
     {
+        case GL_DRAW_INDIRECT_BUFFER_BINDING:
         case GL_MAX_FRAMEBUFFER_WIDTH:
         case GL_MAX_FRAMEBUFFER_HEIGHT:
         case GL_MAX_FRAMEBUFFER_SAMPLES: