[SPv2] Decomposite otherwise-compositable animations that paint nothing.

third_party/WebKit/LayoutTests/FlagExpectations/enable-slimming-paint-v2

 # Expectations for slimming paint v2
 # See: https://docs.google.com/document/d/1QCM912Dr6u38DqyQqd7pxQxDy8FFOoWMMDq7uAXqKdA/view
 # We are focused on fast/, compositing/, and svg/ with all other directories skipped (for now).
 
 Bug(none) accessibility/ [ Skip ]
-Bug(none) animations/ [ Skip ]
 Bug(none) app_banner/ [ Skip ]
 Bug(none) battery-status/ [ Skip ]
 Bug(none) bindings/ [ Skip ]
 Bug(none) bluetooth/ [ Skip ]
 Bug(none) canvas/ [ Skip ]
 Bug(none) crypto/ [ Skip ]
 Bug(none) css-parser/ [ Skip ]
 Bug(none) css1/ [ Skip ]
 Bug(none) virtual/mojo-loading/css1/ [ Skip ]
 Bug(none) css2.1/ [ Skip ]
@@ skipping 42 matching lines @@
 Bug(none) scrollbars/ [ Skip ]
 Bug(none) scrollingcoordinator/ [ Skip ]
 Bug(none) security/ [ Skip ]
 Bug(none) shadow-dom/ [ Skip ]
 Bug(none) storage/ [ Skip ]
 Bug(none) svg/clip-path/ [ Skip ]
 Bug(none) tables/ [ Skip ]
 Bug(none) third_party/ [ Skip ]
 Bug(none) touchadjustment/ [ Skip ]
 Bug(none) transforms/ [ Skip ]
-Bug(none) transitions/ [ Skip ]
 Bug(none) traversal/ [ Skip ]
 Bug(none) typedcssom/ [ Skip ]
 Bug(none) usb/ [ Skip ]
 Bug(none) vibration/ [ Skip ]
 Bug(none) wake_lock/ [ Skip ]
 Bug(none) web-animations-api/ [ Skip ]
 Bug(none) webaudio/ [ Skip ]
 Bug(none) webexposed/ [ Skip ]
 Bug(none) webmidi/ [ Skip ]
 Bug(none) xmlviewer/ [ Skip ]
@@ skipping 1324 matching lines @@
 # SPv2 correctly positions a background clip that includes the transformed size of div #two.
 # SPv1 does not understand how to apply transforms properly in PaintLayerClipper (the issue is
 # also tracked in crbug.com/548184).
 # transforms/transform-overflow.html
 
 # Subpixel adjustments due to differences in compositing
 Bug(none) svg/custom/use-css-events.svg [ Failure ]
 Bug(none) svg/text/text-layout-crash.html [ Failure ]
 Bug(none) compositing/overflow/do-not-paint-outline-into-composited-scrolling-contents.html [ Failure ]
 
-# Some work remains to fully support composited animation and scrolling.
+# Some work remains to fully support composited animation.
+crbug.com/674317 transitions/opacity-transform-transitions-inside-iframe.html [ Timeout ]
+crbug.com/674317 transitions/transition-end-event-destroy-iframe.html [ Timeout ]
 crbug.com/674317 virtual/threaded/animations/composited-filter-webkit-filter.html [ Failure ]
+crbug.com/674317 virtual/threaded/animations/composited-animation-independent-transform-cancel.html [ Failure ]
 crbug.com/674317 virtual/threaded/animations/compositor-independent-transform-cancel.html [ Failure ]
-crbug.com/692310 virtual/threaded/animations/sample-on-last-keyframe.html [ Timeout ]
 crbug.com/674317 virtual/threaded/animations/skew-notsequential-compositor.html [ Failure ]
-crbug.com/674317 virtual/threaded/animations/zoom-responsive-transform-animation.html [ Timeout ]
-crbug.com/674317 virtual/threaded/fast/scroll-behavior/first-scroll-runs-on-compositor.html [ Timeout ]
-crbug.com/674317 virtual/threaded/fast/scroll-behavior/smooth-scroll/fixed-background-in-iframe.html [ Crash Failure ]
-crbug.com/674317 virtual/threaded/fast/scroll-behavior/smooth-scroll/main-thread-scrolling-reason-added.html [ Timeout ]
-crbug.com/674317 virtual/threaded/fast/scroll-behavior/smooth-scroll/main-thread-scrolling-reason-correctness.html [ Timeout ]
-crbug.com/674317 virtual/threaded/fast/scroll-behavior/smooth-scroll/mousewheel-scroll-interrupted.html [ Timeout ]
-crbug.com/674317 virtual/threaded/transitions/extra-transition.html [ Timeout ]
 crbug.com/674317 virtual/threaded/transitions/opacity-transform-transitions-inside-iframe.html [ Timeout ]
-crbug.com/674317 virtual/threaded/transitions/opacity-transition-zindex.html [ Timeout ]
 crbug.com/674317 virtual/threaded/transitions/transition-end-event-destroy-iframe.html [ Timeout ]
-crbug.com/674317 virtual/threaded/transitions/unprefixed-transform.html [ Timeout ]
 
 # Compositor Worker logic has not yet been fully ported to SPv2.
 crbug.com/686897 virtual/threaded/fast/compositorworker/compositor-attribute-change-worker.html [ Timeout ]
 crbug.com/686897 virtual/threaded/fast/compositorworker/compositor-proxy-disconnect-worker.html [ Timeout ]
 crbug.com/686897 virtual/threaded/fast/compositorworker/visual-update.html [ Timeout ]
 crbug.com/686897 virtual/threaded/fast/compositorworker/basic-plumbing-main-to-worker.html [ Crash Failure Timeout ]
 crbug.com/686897 virtual/threaded/fast/compositorworker/basic-plumbing-worker-to-main.html [ Crash Failure Timeout ]
 
 # virtual/threaded variants of sub-directories and tests already skipped or marked as failing above.
 Bug(none) virtual/threaded/inspector/ [ Skip ]
@@ skipping 10 matching lines @@
 # and minor border radius clipping differences. Some SPv2 change is being ticked by the border
 # painting code.
 Bug(700530) fast/css/background-clip-values.html [ Failure ]
 Bug(700530) svg/text/small-fonts-in-html5.html [ Failure ]
 Bug(700530) compositing/overflow/paint-neg-z-order-descendants-into-scrolling-contents-layer.html [ Failure ]
 Bug(700530) fast/multicol/tall-content-in-inner-with-fixed-height.html [ Failure ]
 Bug(700530) svg/W3C-SVG-1.1/animate-elem-05-t.svg [ Failure ]
 Bug(700530) compositing/geometry/abs-position-inside-opacity.html [ Failure ]
 Bug(700530) fast/forms/select-popup/popup-menu-appearance-zoom110.html [ Failure ]
 Bug(700530) fast/css3-text/css3-text-decoration/text-underline-position/text-underline-position-cjk.html [ Failure ]