Transfer user activation in other renderer processes through IPC

In order to complete transferring user activation through cross-process
postMessage, we need to transfer the user activation state in other
renderer processes (non-source, non-target) through IPC.

We will complete the same-process postMessage case in the following CL.

Bug:928838

Change-Id: Ia959d8f43f1965b59674346e83b453bb6f2378ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1546675
Commit-Queue: Lan Wei <lanwei@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Alex Moshchuk <alexmos@chromium.org>
Reviewed-by: Mustaq Ahmed <mustaq@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652411}
19 files changed