In https://bugs.webkit.org/show_bug.cgi?id=45640, we added a more complicated heuristic to determine whether drawing may cause a flash of unstyled content. The WebCore::Document::mayCauseFlashOfUnstyledContent method is called during every WebCore::RenderBlock::paintContents and WebCore::RenderLayer::paintLayer, both of which may be called many times on a complex page. The additional complexity adds measurable overhead to these methods.
Okay, I'll remove mayCauseFlashOfUnstyledContent() usage.
I'd like to keep mayCauseFlashOfUnstyledContent() definition to possibly use it
on browser's paint() side, instead of preventing repaint() as we are doing now.
Created attachment 89891 [details]
I changed my mind to just roll it out.
Committed r84066: <http://trac.webkit.org/changeset/84066>