GitLab

AssistantWebView is the host for embedding the web contents used by
Assistant Settings and Reminders. Previously, AssistantWebView did
not handle either single- or multi-process mash, so the web contents
would not be embedded.

Now, we use Content Service which works in both single- and multi-
process mash in the same pattern established for AppList in:
https://chromium-review.googlesource.com/c/chromium/src/+/1269622

This required adding a few new abilities to NavigableContents that
Assistant has the need for:
- Adding min/max size for auto resizing.
- Adding ability to navigate backwards in history stack.
- Adding handling for target="_blank" links.

Still TODO: Do the same for the Assistant cards that are embedded in
Assistant's UiElementContainerView. Once this is complete, we will be
able to remove WebContentsManager and associated classes/logic :)

Bug: b:78078693
Change-Id: I4dd19a0a4c9506fc6b7f065d54fc1a75132d278f
Reviewed-on: https://chromium-review.googlesource.com/c/1313745
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Reviewed-by: Ken Rockot <rockot@google.com>
Cr-Commit-Position: refs/heads/master@{#606966}