Make RenderFrameHostManager swap RenderFrameHosts, not RenderViewHosts.

We still only have a RFHM for the main frame and not subframes, unless
the --site-per-process flag is passed. To external callers, RFHM is
still effectively swapping RenderViewHosts.

RenderFrameHosts now indirectly keep their RenderViewHosts alive.

Second attempt, after fixing memory leak from http://crrev.com/241151.

R=nasko@chromium.org
TBR=jam@chromium.org
BUG=314791
TEST=No visible behavior change.

Review URL: https://codereview.chromium.org/108483008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241363 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241363
rAc: remove http:// support, except when flag is provided

Add a new flag for this purpose, --reduce-security-for-testing. This is intended to be useful for other security-restricted features as well.

Never show the warning notification in the dialog.

BUG=272512
TBR=joi@chromium.org,sky@chromium.org,akalin@chromium.org

Review URL: https://codereview.chromium.org/100473013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@241364 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 241364