Per recent updates to the WebGL spec, readPixels must be updated to take an ArrayBufferView as argument rather than returning a newly allocated one. Checks on the type and size of the passed array must be implemented.
I've already got a patch in progress for this one. Reassigning to myself.
Created attachment 58293 [details]
Ran WebGL tests in WebKit; testing in Chromium in progress and will be completed before checkin.
Created attachment 58294 [details]
Fixed minor style issue in read-pixels.html test.
Comment on attachment 58294 [details]
Committed r60914: <http://trac.webkit.org/changeset/60914>