merge_pr_15492
This CL allows the main frame to produce a long task that is observed by the child frame. Such a long task can be detected because the attribution will be same-origin-ancestor. Bug: 927866 Change-Id: I38849b5f44172cbffd25f3ab429b0c1a96b0f1e3 Reviewed-on: https://chromium-review.googlesource.com/c/1480114 Reviewed-by: Timothy Dresser <[email protected]> Commit-Queue: Nicolás Peña Moreno <[email protected]> Cr-Commit-Position: refs/heads/master@{#634243}