Add Surface::waitForNextFrame

We can use this for cases like SurfaceView
where one thread (e.g. the framework code)
wants to wait for an unknown client thread
to render a frame in to the surface before
we report it as shown to the window manager.

Bug: 22207948
Change-Id: I9d3344aa1c0ab0f0efd9df24e90ce0410d5f2e22