Decouple vbo validation from LLDrawInfo. Such required vbo's to be initialized before drawinfo creation/modification, which is no longer the case with llvovolume. ('RenderDelayVBUpdate'[although removed in Singu] also fails the same assumption.)

indra/newview/llvograss.cpp

@@ -777,6 +777,11 @@ void LLGrassPartition::getGeometry(LLSpatialGroup* group)
 		}
 	}
 
+	if(vertex_count > 0)
+	{
+		buffer->validateRange(0,  vertex_count - 1, index_count, 0);
+	}
+
 	buffer->flush();
 	mFaceList.clear();
 }