Reduce creation of ViewsDelegate

By consolidating override of OnBeforeWidgetInit that finds shell many
of the places that were setting a viewsdelegate no longer need to.

Also, made AshTestHelper install a ViewsDelegate so that tests don't have.

Because of removed an include of views_delegate from ash_test_helper I had to update some includes.

BUG=none
TEST=none
[email protected]

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=270290

Review URL: https://codereview.chromium.org/280863002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@270399 0039d316-1c4b-4281-b951-d872f2087c98
23 files changed