Merge change Ic03d28b9 into eclair

* changes:
  Check that the window which wants to force hide is visible before setting the flag forceHiding to true. If we do layout the surfaces again this flag gets set no matter what since the keyguard window is always present in the list of tokens and this hides the window which would have become visible since the keyguard just got dismissed. This causes unnecessary focus changes due to changes in visibility of current window.