[ntp4] Treat the root-node and bookmarks-bar-node as a single item.
[ntp4] Treat the root-node and bookmarks-bar-node as a single item.

(This is a re-land for http://codereview.chromium.org/7670034/. No changes.)

BUG=none
Review URL: http://codereview.chromium.org/7671051

git-svn-id: de016e52bd170d2d4f2344f9bf92d50478b649e0@97364 0039d316-1c4b-4281-b951-d872f2087c98

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