SW Pipeline: UnsupportedOperationException in SwingInterOp

This is a regression from j2d pipeline.

Stack trace:

[java] java.lang.UnsupportedOperationException: readPixels:unimp
     [java] at com.sun.prism.sw.SWRTTexture.readPixels(SWRTTexture.java:42)
     [java] at com.sun.javafx.tk.quantum.EmbeddedPainter.run(EmbeddedPainter
.java:96)
     [java] at java.util.concurrent.Executors$RunnableAdapter.call(Executors
.java:471)
     [java] at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureT
ask.java:351)
     [java] at java.util.concurrent.FutureTask.runAndReset(FutureTask.java:1
78)
     [java] at com.sun.prism.render.RenderJob.run(RenderJob.java:37)
     [java] at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolE
xecutor.java:1110)
     [java] at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPool
Executor.java:603)
     [java] at com.sun.javafx.tk.quantum.QuantumRenderer$PipelineRunnable.ru
n(QuantumRenderer.java:98)
     [java] at java.lang.Thread.run(Thread.java:722)
     [java] java.lang.UnsupportedOperationException: readPixels:unimp
     [java] at com.sun.prism.sw.SWRTTexture.readPixels(SWRTTexture.java:42)
     [java] at com.sun.javafx.tk.quantum.EmbeddedPainter.run(EmbeddedPainter
.java:96)
     [java] at java.util.concurrent.Executors$RunnableAdapter.call(Executors
.java:471)
     [java] at java.util.concurrent.FutureTask$Sync.innerRunAndReset(FutureT
ask.java:351)