[10] Review request: JDK-8181976 - Specifying desired dimensions for Image with HiDPI (@2x) variant gets the size wrong

[Jim Graham]

JBS: https://bugs.openjdk.java.net/browse/JDK-8181976
webrev: http://cr.openjdk.java.net/~flar/JDK-8181976/webrev.00/

Simple fix is to carry the double "size requested" values all the way down to where the image pixel scale is determined 
(not strictly required, but important for precision) and then to scale them with the final image pixel scale before 
rounding to integer and using them to resize the thumbnail...

			...jim