[webkit-reviews] review denied: [Bug 96087] Optimize painting of composited scrolling layers : [Attachment 165964] Patch

[bugzilla-daemon at webkit.org]

Simon Fraser (smfr) <simon.fraser at apple.com> has denied Sami Kyöstilä
<skyostil at chromium.org>'s request for review:
Bug 96087: Optimize painting of composited scrolling layers
https://bugs.webkit.org/show_bug.cgi?id=96087

Attachment 165964: Patch
https://bugs.webkit.org/attachment.cgi?id=165964&action=review

------- Additional Comments from Simon Fraser (smfr) <simon.fraser at apple.com>
View in context: https://bugs.webkit.org/attachment.cgi?id=165964&action=review


> Source/WebCore/ChangeLog:22
> +	   This patch enables two optimization for composited scrolling layers:
first,
> +	   when the layer scroll offset changes, do not mark the entire layer
as needing
> +	   display, because the compositor will account for the corresponding
layout
> +	   change simply by translating the layer to the correct position.
> +
> +	   Second, overflow clipping is disabled when painting the contents of
a
> +	   composited scrolling layer. This is done to increase the chances
there is
> +	   valid layer content for the compositor to draw while scrolling the
layer off
> +	   the main thread.
> +
> +	   In order to test these changes, the existing TestRunner display()
method is
> +	   extended to also work with composited layers. This is done by
painting all
> +	   composited layers with a dark transparent mask. Any further repaints
to the
> +	   layer contents will not have this mask, so they will appear
highlighted compared
> +	   to the old contents.

You should break this into three patches. Do the last one first.