We haven't run under-paint-invalidation checking for some time. https://codereview.chromium.org/2049263003/ will enable both rect and object under-invalidation checking for repaint tests. The following tests failed on try bots:
compositing/overflow/updating-scrolling-container-and-content.html
fast/events/message-port-gc-closed-cloned.html
fast/repaint/align-self-overflow-change.html
fast/repaint/background-resize-height.html
fast/repaint/background-resize-width.html
fast/repaint/hover-invalidation-table.html
fast/repaint/justify-self-overflow-change.html
fast/repaint/mix-blend-mode-separate-stacking-context.html
fast/repaint/selected-replaced.html
fast/table/border-collapsing/cached-change-row-border-color.html
fast/table/border-collapsing/cached-change-tbody-border-color.html
paint/invalidation/invalidate-after-composited-scroll-of-window.html
paint/invalidation/invalidate-descendants-when-receiving-paint-layer.html
svg/repaint/rounded-rect-height-change.html
virtual/pointerevent/fast/events/message-port-gc-closed-cloned.html
virtual/prefer_compositing_to_lcd_text/compositing/overflow/updating-scrolling-container-and-content.html
virtual/trustedeventsdefaultaction/fast/events/message-port-gc-closed-cloned.html
Comment 1 Deleted