Bug 99135 – Change creation of layer when blendmode is set

• Status: RESOLVED
• Resolution: WONTFIX
• Component: CSS

[Rik Cabanier]

The current code always creates a layer when it sees a blend mode.
This is not always necessary since Core Graphics supports this idiom.

This patch will change the code so it no longer creates a layer. Subsequent patches are needed for cases that layers are needed such as when there is video, nested blending or filters.

[Rik Cabanier]

Created attachment 168358 [details]
Patch

[Simon Fraser (smfr)]

Comment on attachment 168358 [details]
Patch

You need to change RenderLayerCompositor::requiresCompositingForIndirectReason() to make a compositing layer when blending is on, when children are composited.

You need a test that has a blended div with a 3d-transformed descendant to test this.

[Rik Cabanier]

(In reply to comment #2)
> (From update of attachment 168358 [details])
> You need to change RenderLayerCompositor::requiresCompositingForIndirectReason() to make a compositing layer when blending is on, when children are composited.
> 
> You need a test that has a blended div with a 3d-transformed descendant to test this.

I know that this is not a complete patch.
As we discussed, I want to land the CG code first but the tests won't work since the layer negates the effect of blending.