Fix plugin (and other) block settings for windows opened simply with

      window.open(). Such cases should inherit settings from the parent.

BUG=39740
TEST=TODO
TBR=darin

Review URL: http://codereview.chromium.org/1524014

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@43792 0039d316-1c4b-4281-b951-d872f2087c98