Start drawing immediately

We used to have a condition to start drawing only in the second traversal,
which added a delay of about 10-15ms. We believe that we don't need this
anymore, because we have other means of synchronizing the app transition
animation with the app drawing - we wait for all surfaces to be drawn
in window manager.

Bug: 21035872
Change-Id: I5094a1377817dc7e0a2392cc8f522e99cd7b4d6e