The plan is to make RenderLayer::paintLayerContents() choose between different implementations for painting the composited phases. The first implementation is the existing one: multiple passes into the drawing GraphicsContext. In the following patch, a new implementation will be introduced: multiple passes into multiple DisplayLists. Then this implementation will be changed to be: single pass into multiple DisplayLists.
Created attachment 345462 [details] Patch for EWS
Created attachment 345473 [details] Patch for Review
Comment on attachment 345462 [details] Patch for EWS Attachment 345462 [details] did not pass win-ews (win): Output: https://webkit-queues.webkit.org/results/8602333 New failing tests: http/tests/security/contentSecurityPolicy/userAgentShadowDOM/allow-video.html
Created attachment 345480 [details] Archive of layout-test-results from ews200 for win-future The attached test failures were seen while running run-webkit-tests on the win-ews. Bot: ews200 Port: win-future Platform: CYGWIN_NT-6.1-2.9.0-0.318-5-3-x86_64-64bit
<rdar://problem/42986513>