[SPv2] Add CSS mix-blend-mode support

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) css2.1/ [ Skip ]
 Bug(none) css3/ [ Skip ]
+Bug(none) css3/blending [ Pass ]
 Bug(none) cssom/ [ Skip ]
 Bug(none) csspaint/ [ Skip ]
 Bug(none) custom-elements/ [ Skip ]
 Bug(none) dialog/ [ Skip ]
 Bug(none) dom/ [ Skip ]
 Bug(none) editing/ [ Skip ]
 Bug(none) fonts/ [ Skip ]
 Bug(none) fragmentation/ [ Skip ]
 Bug(none) fullscreen/ [ Skip ]
 Bug(none) gamepad/ [ Skip ]
@@ skipping 2125 matching lines @@
 crbug.com/654554 fast/forms/suggestion-picker/week-suggestion-picker-appearance.html [ Crash Timeout ]
 
 crbug.com/667071 svg/foreignObject/vertical-foreignObject.html [ Failure ]
 
 Bug(none) fast/deprecated-flexbox/009-horizontal.html [ Failure ]
 Bug(none) fast/deprecated-flexbox/009.html [ Failure ]
 Bug(none) fast/overflow/003.xml [ Failure ]
 Bug(none) fast/overflow/overflow-float-stacking.html [ Failure ]
 Bug(none) fast/overflow/overflow-stacking.html [ Failure ]
 
+Bug(none) css3/blending/background-blend-mode-overlapping-accelerated-elements.html [ Failure ]
+Bug(none) css3/blending/effect-background-blend-mode-stacking.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-2nd-stacking-context-composited.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-composited-layers.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-composited-reason-children.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-has-ancestor-clipping-layer.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-isolation-2-stacking-contexts.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-isolation-layer.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-isolation-remove.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-multiply.html [ Failure ]
+Bug(none) css3/blending/mix-blend-mode-with-masking.html [ Failure ]
+Bug(none) css3/blending/svg-blend-color-burn.html [ Failure ]
+Bug(none) css3/blending/svg-blend-color-dodge.html [ Failure ]
+Bug(none) css3/blending/svg-blend-color.html [ Failure ]
+Bug(none) css3/blending/svg-blend-darken.html [ Failure ]
+Bug(none) css3/blending/svg-blend-difference.html [ Failure ]
+Bug(none) css3/blending/svg-blend-exclusion.html [ Failure ]
+Bug(none) css3/blending/svg-blend-hard-light.html [ Failure ]
+Bug(none) css3/blending/svg-blend-hue.html [ Failure ]
+Bug(none) css3/blending/svg-blend-layer-mask.html [ Failure ]
+Bug(none) css3/blending/svg-blend-lighten.html [ Failure ]
+Bug(none) css3/blending/svg-blend-luminosity.html [ Failure ]
+Bug(none) css3/blending/svg-blend-multiply-alpha.html [ Failure ]
+Bug(none) css3/blending/svg-blend-multiply.html [ Failure ]
+Bug(none) css3/blending/svg-blend-overlapping-elements.html [ Failure ]
+Bug(none) css3/blending/svg-blend-overlay.html [ Failure ]
+Bug(none) css3/blending/svg-blend-saturation.html [ Failure ]
+Bug(none) css3/blending/svg-blend-screen.html [ Failure ]
+Bug(none) css3/blending/svg-blend-soft-light.html [ Failure ]
+Bug(none) css3/blending/svg-isolation-foreign-no-isolation.html [ Failure ]
+
+# Failures due to rounding differences
+crbug.com/589265 css3/blending/mix-blend-mode-isolated-group-1.html [ Failure ]
+crbug.com/589265 css3/blending/mix-blend-mode-isolated-group-3.html [ Failure ]
+
+# Failures due to frame scrollbars not painted
+crbug.com/589279 css3/blending/background-blend-mode-data-uri-svg-image.html [ Failure ]
+
 # Notes about rebaselined tests:
 #
 # Rebaselined for small pixel differences.
 # compositing/geometry/layer-due-to-layer-children-deep.html
 #
 # Rebaselined because GeometryMapper applies a control clip for the input element; SPv1 does not.
 # fast/css/input-search-padding.html
 # fast/forms/search/search-vertical-alignment.html
 # fast/forms/search/searchfield-heights.html
 # fast/forms/text/text-font-height-mismatch.html
 # fast/forms/text/textfield-overflow-by-value-update.html
 # fast/replaced/width100percent-searchfield.html
 #
 # 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