Use the attached test case, When the images slide(using CSS transfrom:rotate-3d) The background layer images are still there, And memory is leaking Well, Firefox renders this case good.
Verified at a recent QtWebKit and Chrome 27. But Qt-5.0.2 WebKit has no such problem. So maybe this problem has been fixed in trunk.
Created attachment 203992 [details] A simple test case for css transform animation using setInterval & translate-3d
This case occurs at Qt-4.8.x with "-platform xlibgl" enable and WebKit with a version at 2012/3/7 nearby. Since Qt-5 has switched to xcb, and dropped xlib(and xlibgl also) support, this may not be fixed in the future?
Source\WebCore\platform\graphics\texmap\TextureMapper.cpp: TextureMapper uses TextureMapperImageBuffer, though macro switch USE(ACCELERATED_COMPOSITING) is ON.
Bug 102011 seems to be related to this problem.
Problem fixed: This is due to under opengl graphics driver not supporting multi-sample feature, combined with Qt-4.8.x's not correctly fbo pool implementation. #see https://bugreports.qt-project.org/browse/QTBUG-31891