When --enable-display-compositor-pixel-dump is turned on, this list of layout tests fail because their background size (the size of the captured image) changes size. For most of them, the size doubles. I am bisecting this now, and will comment on the revision range when I have it.
fast/backgrounds/gradient-background-leakage-hidpi.html
fast/canvas/canvas-hidpi-blurry.html
fast/hidpi/broken-image-icon-hidpi.html
fast/hidpi/broken-image-with-size-hidpi.html
fast/hidpi/clip-text-in-hidpi.html
fast/hidpi/device-scale-factor-paint.html
fast/hidpi/focus-rings.html
fast/hidpi/gradient-with-scaled-ancestor.html
fast/hidpi/resize-corner-hidpi.html
fast/hidpi/scrollbar-appearance-increase-device-scale-factor.html
fast/sub-pixel/shadows-hidpi.html
paint/markers/grammar-markers-hidpi.html
paint/markers/inline-spelling-markers-hidpi-composited.html
paint/markers/inline-spelling-markers-hidpi.html
scrollbars/resize-scales-with-dpi-150.html
svg/as-image/image-respects-deviceScaleFactor.html
svg/custom/masking-clipping-hidpi.svg
virtual/gpu/fast/canvas/canvas-hidpi-blurry.html
virtual/prefer_compositing_to_lcd_text/scrollbars/resize-scales-with-dpi-150.html
Comment 1 by masonfreed@chromium.org
, Oct 15