Bug 198454 - Optimize for negative z children on the root
Summary: Optimize for negative z children on the root
Status: NEW
Alias: None
Product: WebKit
Classification: Unclassified
Component: Compositing (show other bugs)
Version: WebKit Nightly Build
Hardware: Unspecified Unspecified
: P2 Normal
Assignee: Simon Fraser (smfr)
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2019-06-01 10:55 PDT by Simon Fraser (smfr)
Modified: 2019-06-01 10:59 PDT (History)
3 users (show)

See Also:

Attachments
Testcase (1.69 KB, text/html)
2019-06-01 10:55 PDT, Simon Fraser (smfr) 		no flags Details
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Description Simon Fraser (smfr) 2019-06-01 10:55:22 PDT 
Created attachment 371114 [details]
Testcase

It's pretty common to have negative z-index children in the root stacking context. Currently, we'll pop in to adding a foreground layer, which will become tiled and double our tiled backing store memory use.

We could, in some cases, use the page tiles for the foreground, and just have a solid color background behind the negative z-index child.