The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/8780ab5722f24aa3f463b2b5838b5ae229b3f946

commit 8780ab5722f24aa3f463b2b5838b5ae229b3f946
Author: imcheng <imcheng@chromium.org>
Date: Tue May 02 04:28:10 2017

[DIAL tests] Slightly improve DialRegistry tests.

Update the TestDeviceExpires test case with a slightly more complicated
scenario.

Also, to make the tests more robust, we will use a testing clock to
generate the base::Time for various objects. DialRegistry::Now() is
replaced with a clock that can be swapped out in tests.

BUG= 661457 

Review-Url: https://codereview.chromium.org/2843653002
Cr-Commit-Position: refs/heads/master@{#468556}

[modify] https://crrev.com/8780ab5722f24aa3f463b2b5838b5ae229b3f946/chrome/browser/media/router/discovery/dial/dial_registry.cc
[modify] https://crrev.com/8780ab5722f24aa3f463b2b5838b5ae229b3f946/chrome/browser/media/router/discovery/dial/dial_registry.h
[modify] https://crrev.com/8780ab5722f24aa3f463b2b5838b5ae229b3f946/chrome/browser/media/router/discovery/dial/dial_registry_unittest.cc