Now ensures the visibility of the last items added to the list when the last item was visible before we added new ones.
Now ensures the visibility of the last items added to the list when the last item was visible before we added new ones.

Review URL: http://codereview.appspot.com/181079

git-svn-id: db59699583a60be9a535cd09cdc9132301867226@14 15e8cca8-e42c-11de-a347-f34a4f72eb7d

Eloston/syzygy,wangming28/syzygy,sebmarchand/syzygy,google/syzygy,pombreda/syzygy,sebmarchand/syzygy,Eloston/syzygy,wangming28/syzygy,pombreda/syzygy,google/syzygy,ericmckean/syzygy,wangming28/syzygy,supriyantomaftuh/syzygy,pombreda/syzygy,supriyantomaftuh/syzygy,ericmckean/syzygy,ericmckean/syzygy,google/syzygy,sebmarchand/syzygy,sebmarchand/syzygy,sebmarchand/syzygy,supriyantomaftuh/syzygy,supriyantomaftuh/syzygy,pombreda/syzygy,google/syzygy,ericmckean/syzygy,pombreda/syzygy,wangming28/syzygy,ericmckean/syzygy