If the file to rename doesn't exist, return OK immediately.

This matches the behavior of ChromiumEnv::RenameFile and should prevent
at least some unnecesary retries of renames.

Bug: 732701, 732863
Change-Id: I76637ba5f1f081f3709add94f4a085f54be0e096
Reviewed-on: https://chromium-review.googlesource.com/537134
Reviewed-by: Michael Nordman <michaeln@chromium.org>
Commit-Queue: Marijn Kruisselbrink <mek@chromium.org>
Cr-Commit-Position: refs/heads/master@{#479785}
1 file changed