[webkit-reviews] review denied: [Bug 69796] Support creating composited layers for fixed position elements : [Attachment 111876] Patch

[bugzilla-daemon at webkit.org]

Simon Fraser (smfr) <simon.fraser at apple.com> has denied Vangelis Kokkevis
<vangelis at chromium.org>'s request for review:
Bug 69796: Support creating composited layers for fixed position elements
https://bugs.webkit.org/show_bug.cgi?id=69796

Attachment 111876: Patch
https://bugs.webkit.org/attachment.cgi?id=111876&action=review

------- Additional Comments from Simon Fraser (smfr) <simon.fraser at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=111876&action=review


You need to check that the

> Source/WebCore/rendering/RenderLayerCompositor.cpp:1504
> +    // position:fixed elements that create their own stacking context (e.g.
have an explicit z-index,
> +    // opacity, transform) can get their own composited layer.
> +    if (!(renderer->isPositioned() && renderer->style()->position() ==
FixedPosition && layer->isStackingContext()))
> +	   return false;

This will incorrectly return true for a position:fixed element inside a
transformed one. You should also consider nested position:fixed too. Both need
test cases.

You want to check that the container() of the renderer is the RenderView, but
beware; this method may be called before the renderers have been hooked up.