[GTK] imported/w3c/web-platform-tests/css/css-transforms/perspective-transforms-equivalence.html is failing This test case renders four 3D transformed semi-transparent layers. This seems like a bug of semi-transparent layers and a depth buffer. See also: Bug 217103 – [TextureMapper] A semi-transparent parent layer is rendered as a opaque layer for children layers Bug 217080 – [TextureMapper] Order Independent Transparency support