GitLab

Following earlier cleanups, TempFile is now just a wrapper around
base::File anyway.

BUG=302078
TEST=e.g. NaClBrowserTestPnacl.PPAPICore (tests PNaCl translation)

Review URL: https://codereview.chromium.org/1615523003

Cr-Commit-Position: refs/heads/master@{#370752}