Replace RunUntilIdle() with a quit callback in ServiceWorkerJobTest

This patch replaces the base::RunLoop().RunUntilIde() with base::RunLoop loop,
which will reduce the time delay and make those unit tests deterministic.

Bug: 973005
Change-Id: I3fa718ef0926b38385c53f0af9d6ce8865a87660
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1760670
Commit-Queue: Makoto Shimazu <shimazu@chromium.org>
Reviewed-by: Makoto Shimazu <shimazu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#691968}

AUTHORS

@@ -957,6 +957,7 @@ Wanming Lin <wanming.lin@intel.com>
 Wei Li <wei.c.li@intel.com>
 WenSheng He <wensheng.he@samsung.com>
 Wesley Lancel <wesleylancel@gmail.com>
+Wei Wang <wei4.wang@intel.com>
 Wesley Wigham <wwigham@gmail.com>
 Will Hirsch <chromium@willhirsch.co.uk>
 Will Shackleton <w.shackleton@gmail.com>