GitLab

Current efforts are aimed at harmonizing our UI code. #ifdefs work
against this and have a lot of downsides besides.

This is a follow-up to http://crrev.com/351683002 -- a long-running CL
which added ShowLinkDisambiguationPopup to Aura -- and
http://crrev.com/596373002 which fixed some build problems with that.
However, toolkit_views=1 use_aura=0 which is in use on Mac still has
problems.

This CL adds default method definitions to WebContentsViewDelegate and
RenderWidgetHostViewBase. Essentially moving a NOTIMPLEMENTED() guarded
by #ifdefs into a base class method, and removing some unnecessary
boilerplate.

BUG=385249, 399191

Review URL: https://codereview.chromium.org/610893003

Cr-Commit-Position: refs/heads/master@{#297360}