When cross-site navigations are cancelled, delete the
ResourceLoader that would have been trasferred to the
new renderer. These were being leaked, and would keep
a lock on disk cache entries, making a page impossible
to visit after a cancelled cross site navigation to it.

BUG=341134

Review URL: https://codereview.chromium.org/143183009

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251561 0039d316-1c4b-4281-b951-d872f2087c98
Callback, brought to you by the letter B.

BUG=none
TEST=no change

Review URL: https://codereview.chromium.org/166663005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@251562 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 251562