We should get rid of TileController's CoverageForSlowScrolling. The mode creates large tiles so that we will paint less for these sites. At one time, that was an important performance improvement because a lot of sites were still in slow scrolling mode. Now that very few sites fall into that mode, we should get rid of it since it just adds complexity.
Created attachment 223396 [details] Patch
Created attachment 223397 [details] Patch with layout test results
Comment on attachment 223397 [details] Patch with layout test results View in context: https://bugs.webkit.org/attachment.cgi?id=223397&action=review > LayoutTests/platform/mac-wk2/tiled-drawing/tile-coverage-slow-scrolling-expected.txt:-12 > - (tile size 800 x 600) is there any reason to keep this test around?
(In reply to comment #3) > (From update of attachment 223397 [details]) > View in context: https://bugs.webkit.org/attachment.cgi?id=223397&action=review > > > LayoutTests/platform/mac-wk2/tiled-drawing/tile-coverage-slow-scrolling-expected.txt:-12 > > - (tile size 800 x 600) > > is there any reason to keep this test around? Not unless we want a test to document this moment. :-)
Comment on attachment 223396 [details] Patch View in context: https://bugs.webkit.org/attachment.cgi?id=223396&action=review > Source/WebCore/rendering/RenderObject.cpp:1291 > + if (!shouldClipToLayer && repaintContainer == view) > + repaintRect = pixelSnappedIntRect(view->backgroundRect(view)); This confuses me. Do we ever have !shouldClipToLayer when |this| != view?
(In reply to comment #5) > (From update of attachment 223396 [details]) > View in context: https://bugs.webkit.org/attachment.cgi?id=223396&action=review > > > Source/WebCore/rendering/RenderObject.cpp:1291 > > + if (!shouldClipToLayer && repaintContainer == view) > > + repaintRect = pixelSnappedIntRect(view->backgroundRect(view)); > > This confuses me. Do we ever have !shouldClipToLayer when |this| != view? Hmm, no I don't think so! I was just being extra careful, but I realize now that is not necessary.
Comment on attachment 223396 [details] Patch Attachment 223396 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/6517240081940480 New failing tests: platform/mac-wk2/tiled-drawing/tile-size-slow-zoomed.html platform/mac-wk2/tiled-drawing/tile-coverage-slow-scrolling.html platform/mac-wk2/tiled-drawing/fixed-background/fixed-non-propagated-body-background.html
Created attachment 223404 [details] Archive of layout-test-results from webkit-ews-14 for mac-mountainlion-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: webkit-ews-14 Port: mac-mountainlion-wk2 Platform: Mac OS X 10.8.5
Created attachment 223501 [details] Patch
Comment on attachment 223501 [details] Patch Attachment 223501 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.appspot.com/results/4912089470599168 New failing tests: compositing/repaint/fixed-background-scroll.html
Created attachment 223508 [details] Archive of layout-test-results from webkit-ews-12 for mac-mountainlion-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: webkit-ews-12 Port: mac-mountainlion-wk2 Platform: Mac OS X 10.8.5
Comment on attachment 223501 [details] Patch Attachment 223501 [details] did not pass mac-ews (mac): Output: http://webkit-queues.appspot.com/results/6079075974119424 New failing tests: compositing/repaint/fixed-background-scroll.html
Created attachment 223512 [details] Archive of layout-test-results from webkit-ews-02 for mac-mountainlion The attached test failures were seen while running run-webkit-tests on the mac-ews. Bot: webkit-ews-02 Port: mac-mountainlion Platform: Mac OS X 10.8.5
Created attachment 223515 [details] Patch This will fix the latest test failure.
Created attachment 223530 [details] Patch
http://trac.webkit.org/changeset/163675