[ZipFileCreator] Recursively zip folders

The ZipFileCreator service now recursively zips folders. Files App
doesn't need to enumerate all the files in folders to zip anymore. This
is done in a much more efficient way by ZipFileCreator.

When zipping a folder containing 100 subfolders with 1000 small
files each (for a total of 100,000 small files) on a kevin device,
the old system takes 144 seconds (listing files 103 seconds + zipping
files 41 seconds), whereas the new system takes only 26 seconds. This
is an improvement by a factor of 5.5.

BUG=chromium:912236
TEST=out/release/zlib_unittests
TEST=out/release/browser_tests --gtest_filter="ZipFileCreatorTest*

Change-Id: I049e25fbc365528c4d9ec12ac2afc58b4d036046
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2912233


Reviewed-by: Dominick Ng <dominickn@chromium.org>
Reviewed-by: Noel Gordon <noel@chromium.org>
Commit-Queue: François Degros <fdegros@chromium.org>
Cr-Commit-Position: refs/heads/master@{#886233}