Bug 741 HiDPI: Simplify ScalableSurface (2): Add request pixelScale API entry, fixed NewtCanvasAWT use-case

We require the requested pixelScale in NewtCanvasAWT if the NEWT window (child)
is not yet realized, so the JAWTWindow can receive the request,
since realized/current pixelScale is still 1.

Remove return value (requested pixel scale):
  -  public int[] setSurfaceScale(final int[] result, final int[] pixelScale);
  +  public void setSurfaceScale(final int[] pixelScale);

Add API hook to query requested pixel scale:
  +  int[] getRequestedSurfaceScale(final int[] result);

Unique name for get[Current]*:
  -  public int[] getSurfaceScale(final int[] result);
  +  public int[] getCurrentSurfaceScale(final int[] result);