It would be ideal for the the section on queries https://gpuweb.github.io/gpuweb/#queries and the command beginPipelineStatisticsQuery() and endPipelineStatisticsQuery() to cross reference each other.

Also, the interface for occlusion is not at all clear to me. Indeed, the interfaces for query is taking 32-bit size integer, but where and how is the buffer decided for the query result to land?

On a related note, it would be ideal that if a buffer contains MAP_READ it can also contain COPY_DST or QUERY_RESOLVE but no other; I am assuming that QUERY_RESOLVE means that the buffer will hold query results.