Implement File rewrite.
This is really a dup of bug 118203. Keeping it open for Chimera visibility.
Bug 118203 was checked into CHIMERA_M1_0_BRANCH, so this is fixed.
that sound you here is saari doing a little dance!
Marking as verified since we know this has been checked in. No real test cases being run to test this specifically, but we know it's fixed a bunch of stuff. :) If there are test cases that we should run to test this though, please lemme know.