GitLab

AssistantResponseObserver will be used in response processing V2. This
CL just introduces the observer, follow up CLs will use it and refine
when its methods are invoked. Currently OnUiElementAdded is fired when
the UI element is added to the response, but in a follow up CL it will
first be pended and pre-processed before being added.

Bug: b:129411551
Change-Id: I905ea9a2322d241fdc609b95b98ebd7713f79bc4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2063034
Commit-Queue: David Black <dmblack@google.com>
Reviewed-by: Xiaohui Chen <xiaohuic@chromium.org>
Cr-Commit-Position: refs/heads/master@{#742455}