Migrate ProfileInfoCache away from BrowserThread::FILE.

R=rch@chromium.org

TBR=oysteine@chromium.org (minor test tweak in c/b/tracing)

Bug: 689520
Change-Id: I61f980da1a30f88b5c5688f1b5c62fa1646f6bf6
Reviewed-on: https://chromium-review.googlesource.com/611127
Commit-Queue: Gabriel Charette <gab@chromium.org>
Reviewed-by: Ryan Hamilton <rch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#494108}
4 files changed