[SPv2] Flatten property trees in PaintRecordBuilder into a single display list.

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) app_banner/ [ Skip ]
 Bug(none) battery-status/ [ Skip ]
 Bug(none) bindings/ [ Skip ]
 Bug(none) bluetooth/ [ Skip ]
 Bug(none) canvas/ [ Skip ]
@@ skipping 1360 matching lines @@
 # Tests that fail after changes to border dash painting, due to antialiasing differences
 # 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) 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 ]
+
+# These are failing due to compositing isolation failures in SVG
+# missing code to account for CompositingRecorder in SPv2 mode, likely).

[pdr., 2017/03/28 21:01:30]

Nit:
# (Likely missing code to account for CompositingRecorder)

[chrishtr, 2017/03/28 21:43:23]

Done.

+crbug.com/665259 svg/as-background-image/svg-as-background-5.html [ Failure ]
+crbug.com/665259 svg/as-background-image/svg-as-background-6.html [ Failure ]
+crbug.com/665259 svg/stroke/non-scaling-stroke-paintserver-same-as-fill.html [ Failure ]
+crbug.com/665259 css3/blending/svg-isolation-svg-img-isolate.html [ Failure ]
+crbug.com/665259 css3/blending/svg-isolation-img-isolate.html [ Failure ]