Providing further information to #RT-29537 the attached netbeans project provides a real world use case where charts or other graphics are rendered in a webview.
In b96, the rendering was correct.
In b97, the rendering started to misbehave and is the same in b98.

I don't know how to add attachments, so I host the project archive here: http://odev.fr/dev/Highcharts.zip.
Screen shots: http://odev.fr/dev/charts-good.png and http://odev.fr/dev/charts-bad.png

The version that displays correctly runs on 1.7 update 25 and not b96.