GitLab

Currently when we share files to ARC, it does not accept any extra data.
However, with the web share support, it is possible to share files with
title and text. This CL adds the support to share extra strings to ARC.

BUG=1127670

Change-Id: I2eeaf4199ad1c2df94be77df0574f046c26f1f95
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2589200Reviewed-by: Dominick Ng <dominickn@chromium.org>
Commit-Queue: Maggie Cai <mxcai@chromium.org>
Cr-Commit-Position: refs/heads/master@{#837028}