Fixes instant so that it correctly deals with child contents. I've
changed around BlockedPopupContainer so that it can handle any types
and made TabContents offer a mode to block all child content.

BUG=58927
TEST=enable instant, go to a site that would normally show a popup on
     entering (or explicitly enable all popups). While typing in
     the omnibox the popup shouldn't appear, but as soon as you
     commit the instant result it should appear.

Review URL: http://codereview.chromium.org/3694005

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@62553 0039d316-1c4b-4281-b951-d872f2087c98
17 files changed