This is a regression since we're calculating the layers' visible rects based on their transform, while ignoring that the transform might change while animating.
Created attachment 123669 [details]
Created attachment 123670 [details]
Attachment 123669 [details] did not pass style-queue:
Failed to run "['Tools/Scripts/check-webkit-style', '--diff-files', u'Source/WebKit2/ChangeLog', u'Source/WebKit..." exit_code: 1
Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.h:38: wtf includes should be <wtf/file.h> instead of "wtf/file.h". [build/include] 
Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.h:38: Alphabetical sorting problem. [build/include_order] 
Total errors found: 2 in 3 files
If any of these errors are false positives, please file a bug against check-webkit-style.
Created attachment 124012 [details]
Comment on attachment 124012 [details]
View in context: https://bugs.webkit.org/attachment.cgi?id=124012&action=review
Seems ok to me
> + // If this layer is part of an active transform animation, the visible rect might change, so we rather render the whole layer
> + // until some better optimization is available.
I would break the line after the second ,. Then they will have almost the same size
> + if (selfOrAncestorHasActiveTransformAnimations())
> + return tiledBackingStoreContentsRect();
Did you do some measurements of this? regarding to the comment in the changelog
> + if (!parent())
> + return false;
> + return toWebGraphicsLayer(parent())->selfOrAncestorHasActiveTransformAnimations();
wouldnt it read nicer
> > Source/WebKit2/WebProcess/WebCoreSupport/WebGraphicsLayer.cpp:553
> > + if (selfOrAncestorHasActiveTransformAnimations())
> > + return tiledBackingStoreContentsRect();
> Did you do some measurements of this? regarding to the comment in the changelog
No... if I had a viable alternative I'd measure it vs. this solution :) Problem is that if I'd calculate the visible rect based on all the transform keyframes, I could still reach a point where a huge layer is entirely visible. What we should probably do in that case is not have content-scale for huge transformed layers, but that should come later as it's tricky.
Created attachment 124015 [details]
Created attachment 124017 [details]
Comment on attachment 124017 [details]
Clearing flags on attachment: 124017
Committed r105934: <http://trac.webkit.org/changeset/105934>
All reviewed patches have been landed. Closing bug.