Overridden allocate() to support direct buffers.

jetty-spdy/spdy-core/src/main/java/org/eclipse/jetty/spdy/api/ByteBufferDataInfo.java

@@ -68,4 +68,10 @@ public class ByteBufferDataInfo extends DataInfo
         }
         return space;
     }
+
+    @Override
+    protected ByteBuffer allocate(int size)
+    {
+        return buffer.isDirect() ? ByteBuffer.allocateDirect(size) : super.allocate(size);
+    }
 }