Remove NOTIFICATION_BROWSER_CLOSED/OPENED from tests.

This covers all non-mac tests that used these notifications. They
now use BrowserListObserver instead.

Additionally, some includes are cleaned up. Specifically, includes
removed from interactive_test_utils.h are added to some testing files
which relied on these transitive includes.

Bug: 268984
Change-Id: I27b68e14e83401e6d938fcf6eb38c431bc1f7b58
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1684512
Reviewed-by: Lei Zhang <[email protected]>
Commit-Queue: Evan Stade <[email protected]>
Cr-Commit-Position: refs/heads/master@{#676219}
51 files changed