Use a per-frame task runner at InstllationServiceImpl

This CL switches task runners at several places from per-thread to
per-frame. The purpose of this change is to make it possible to freeze
tasks for bfcache.

The actual test that executes JavaScript on the task runner is:
browser_tests --gtest_filter=AppBannerManagerDesktopBrowserTest.WebAppBannerFiresAppInstalled

Bug: 913912
Change-Id: I9b6c79cdbeeb96ab03882390a6303598543bed7b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1531898
Reviewed-by: Alexander Timin <altimin@chromium.org>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Commit-Queue: Hajime Hoshi <hajimehoshi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#642467}
1 file changed