Revert 251563 "Move browser initiated navigation from RenderView..."

Speculatively revert to help diagnose bug 345757.
Mainly useful to make it easier to revert r249676, which changes the
lifetime of RenderViewHosts.

> Move browser initiated navigation from RenderViewHost to RenderFrameHost.
> 
> BUG=304341
> TBR=jochen@chromium.org
> 
> Review URL: https://codereview.chromium.org/148083013

TBR=nasko@chromium.org

Review URL: https://codereview.chromium.org/177713006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@253010 0039d316-1c4b-4281-b951-d872f2087c98