Transfer user activation in browser and renderer side

This change is to implement this API:

This Cl transfers user activation state in the frame tree in browser
when |transfer_user_activation| is true, and target's renderer, the
following CL will transfer user activation in other (non-source
non-destination) renderers.

Bug: 928838
Change-Id: I4f07a056616cf2628163d1a059c99923a80789fc
Reviewed-by: Daniel Cheng <>
Reviewed-by: Avi Drissman <>
Reviewed-by: Mustaq Ahmed <>
Commit-Queue: Lan Wei <>
Cr-Commit-Position: refs/heads/master@{#641795}
8 files changed