Remove some RenderViewObserver callbacks

Navigation-related callbacks are already exposed on RenderFrameObserver.
This patch starts using WebTestRenderFrameObserver for these instead of
BlinkTestRunner.

Bug: none
Change-Id: Ia77d2e7ca1cb569f479c24895543bf8b78be4f66
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1576100
Commit-Queue: Dmitry Gozman <dgozman@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653207}
6 files changed