Bug 171652

Summary: Avoid descending to sublayers when coverage rect doesn't change
Product: WebKit Reporter: Antti Koivisto <koivisto>
Component: Layout and RenderingAssignee: Nobody <webkit-unassigned>
Status: NEW ---    
Severity: Normal CC: bfulgham, ggaren, simon.fraser, zalan
Priority: P2    
Version: WebKit Nightly Build   
Hardware: Unspecified   
OS: Unspecified   
Attachments:
Description Flags
patch ggaren: review+

Description Antti Koivisto 2017-05-04 05:30:16 PDT
Currently NeedsComputeVisibleAndCoverageRect is treated as a change that affects sublayers. This is unnecessary if nothing actually changes as a result of the computation.
Comment 1 Antti Koivisto 2017-05-04 05:35:19 PDT
Created attachment 309034 [details]
patch
Comment 2 Geoffrey Garen 2017-05-04 08:29:29 PDT
Comment on attachment 309034 [details]
patch

r=me
Comment 3 Simon Fraser (smfr) 2017-05-04 08:32:08 PDT
Comment on attachment 309034 [details]
patch

Does this help performance in some scenario not mentioned here?
Comment 4 Antti Koivisto 2017-05-04 11:36:15 PDT
No. I just noticed I was trivially leaving some performance on table in the earlier patch. I'm not aware of any real world case where this matters.