libchromeos: Add a default chromeos::MessageLoop to Daemon.

In order to use chromeos::MessageLoop::curent() we need to have an
instance created and set as default. This patch creates the wrapper
for base::MessageLoopForIO in chromeos::Daemon so daemons can use
either interface.

This patch also runs the base::MessageLoopForIO via the
chromeos::MessageLoop wrapper so calls to
chromeos::MessageLoop::BreakLoop() work as expected. This methods was
updated to not use the deprecated Run/QuitNow() methods in the
base::MessageLoop interface and use a base::RunLoop instead.

BUG=chromium:506052
TEST=`FEATURES=test emerge-link libchromeos` still works.`

Change-Id: I16188e399a48923e398fb621875debff01accea7
Reviewed-on: https://chromium-review.googlesource.com/286825
Reviewed-by: Alex Vakulenko <avakulenko@chromium.org>
Trybot-Ready: Alex Deymo <deymo@chromium.org>
Tested-by: Alex Deymo <deymo@chromium.org>
Commit-Queue: Alex Deymo <deymo@chromium.org>
4 files changed