Fix browse fragment smooth scrolling.

In most cases (During layout and when smooth scrolling) we shouldn't add
items until they have scrolled into the window.

On focus search fail we should add items immediately; however the modified
methods are not part of that code flow.

b/18742856

Change-Id: I83bbc583a7809e65ed930353aa804bd95b362eee
(cherry picked from commit e3cbb083dad7a70b26f542b7bb5d7b67a8c8621e)
1 file changed