Bug 128339 – Should get rid of TileController's CoverageForSlowScrolling mode

• Status: RESOLVED
• Resolution: FIXED
• Component: Layout and Rendering

[Beth Dakin]

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.

[Beth Dakin]

Created attachment 223396 [details]
Patch

[Beth Dakin]

Created attachment 223397 [details]
Patch with layout test results

[Tim Horton]

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?

[Beth Dakin]

(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. :-)

[Simon Fraser (smfr)]

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?

[Beth Dakin]

(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.

[Build Bot]

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

[Build Bot]

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

[Beth Dakin]

Created attachment 223501 [details]
Patch

[Build Bot]

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

[Build Bot]

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

[Build Bot]

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

[Build Bot]

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

[Beth Dakin]

Created attachment 223515 [details]
Patch

This will fix the latest test failure.

[Beth Dakin]

Created attachment 223530 [details]
Patch

[Beth Dakin]

http://trac.webkit.org/changeset/163675