GTK: Split out the cookie display into its own component for reuse in the cookie ask dialog.

This patch is fairly different from my previous attempt:
- It's implemented not as a C++ object, but as a gobject. This was originally
  done because there were very weird memory errors and I assume there were
  ownership issues (see point 3), but I'm leaving it this way since I think
  it's a bit simpler to integrate.
- Several details of when it initializes style are now done in response to the
  frame being realized, instead of having to realize widgets in the CookiesView
  to pass in GtkStyles*.
- The CookieView class and its unit tests have been modified with a flag that
  allows it to be stack allocated, which is what the unit tests do. It looks
  like it only accidentally worked previously.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/669015

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@40636 0039d316-1c4b-4281-b951-d872f2087c98
6 files changed