Add unit test for AllowBindings check.

BUG=117418
TEST=none


Review URL: http://codereview.chromium.org/9701038

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@126929 0039d316-1c4b-4281-b951-d872f2087c98
  virtual void UpdatePreferredSize(const gfx::Size& pref_size) {}

  virtual void UpdatePreferredSize(const gfx::Size& pref_size) {}
