Remove unused functions in TestRenderFrameHost

This CL removes functions from TestRenderFrameHost that ar no longer
used. It also removes one function from the public
RenderFrameHostTester interface that is no longer used outside of
content/.

Bug: 728571
Change-Id: I62cadcacc3e4d1ed7b0ca6d1c9ee46cd675a32bc
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1581960
Auto-Submit: Camille Lamy <clamy@chromium.org>
Reviewed-by: Nasko Oskov <nasko@chromium.org>
Commit-Queue: Camille Lamy <clamy@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653958}
3 files changed