Add tests using blending and isolation for body and html elements. Some scenarios: * Child of body should blend with body content, with body's background and, if any, html's background, otherwise, with the white opaque viewport. * If body creates a stacking context, then a child of body should blend with content of body, excluding body's background. * Setting mix-blend-mode on body, all the body contents, excluding background should blend with body's background and (if any) html background. There is a bug: https://bugs.webkit.org/show_bug.cgi?id=75460, saying that body's background will be truncated in this case. * Set mix-blend-mode on html element -> everything should blend with opaque white. * Setting isolation on html should not change anything. * Setting isolation on body should create a stacking context.
Created attachment 230821 [details] Patch
Comment on attachment 230821 [details] Patch r=me
Comment on attachment 230821 [details] Patch Clearing flags on attachment: 230821 Committed r168349: <http://trac.webkit.org/changeset/168349>
All reviewed patches have been landed. Closing bug.