Converting malloc() calls to calloc()

A quick grep suggests that Firefox contains hundreds of malloc() calls
that can be converted to calloc() calls. This is a security improvement,
as it prevents integer overflow attacks. It can also help weed out bugs
because, unlike malloc(), calloc() zeros its memory. The only concern is
the potential performance hit of zeroing the memory.

Is a dev interested in working though the eligible malloc() calls with
me and replacing those that aren't performance-critical?