No review because this is mostly just syncing us with the upstream,
https://cvs.khronos.org/svn/repos/registry/trunk/public/webgl/sdk/tests/
as well as adjusting to test harness changes (now loading test lists asynchronously) and a patch to the harness itself which I'll send upstream (see fix-webgl-harness-async.patch)
This test is valid, but flaky as it relies on GC happening at a particular time. A recent JS engine change making it actually happen caused it to actually catch a bug we've always had in the OES_texture_float impl, see the discussion on bug 630672, and I don't have time to fix that now.