[NTP4] Fix empty apps page crash.

R=estade@chromium.org,csharp@chromium.org
BUG=122214
TEST=Drag, switch to new pane, drop on original nav dot. Drop on newly created
pane. Nothing should asplode.


Review URL: http://codereview.chromium.org/10068001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@132468 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed