In addition to saving the cookies to the file system service (per the
previous patch), we also modify the filesystem service to take a
client. When the shell connection to the file system service is broken,
instead of quitting immediately, we broadcast a shutdown notification to
all of our clients, and wait for them to close the directory objects.
This solves the timing problems during shutdown.
BUG=493311
TBR=shess@chromium.orgR=jam@chromium.org,erikwright@chromium.org
First Review URL: https://codereview.chromium.org/1179413010
Review URL: https://codereview.chromium.org/1231493002
Cr-Commit-Position: refs/heads/master@{#338888}