It's parsing /proc/self/statm, and returning the values as if they were bytes, but they are number of pages, so to get the bytes we need to take the page size into account. In r208534 I added a method to get /proc/self/statm values in bytes to Platform layer, so we can simply use that instead.
Created attachment 294371 [details] Patch
Committed r208538: <http://trac.webkit.org/changeset/208538>