Pull cacheinvalidations code directory into chromium repo.

Code.google.com is being turned down, and cacheinvalidation is still necessary
for Chromium, and depends on base/. Pull it directly into the chromium repo to
preserve it and ensure any changes to base/ that conflict with the
cacheinvalidation code are caught at compile time.

BUG=472898

Review URL: https://codereview.chromium.org/1162033004

Cr-Commit-Position: refs/heads/master@{#332636}
202 files changed