Looking into oop raster layout test failures, I also ran Blink's layout tests (fast/ and compositing/ only) with ganesh and found a number of things that looked wrong in ganesh vs software raster.

You can repro these by:
(1) Applying this patch: https://chromium-review.googlesource.com/c/chromium/src/+/876823
(2) ninja -C out/Debug content_shell image_diff blink_tests && third_party/WebKit/Tools/Scripts/run-webkit-tests -t Debug TESTNAMEHERE

In many cases, you can run chrome with --enable-gpu-rasterization and open up the page directly.  These files are all in third_party/WebKit/LayoutTests/.

Here's the classes of failures I saw:

(1) Gradients (often zero radius) not drawing:
    fast/gradients/crash-on-zero-radius.html
    fast/gradients/css3-radial-gradients2.html
    fast/gradients/radial-centered.html
    fast/gradients/unprefixed-radial-gradients2.html

(2) Gradient with a weird line (doesn't repro in browser, so swiftshader?):
    fast/gradients/conic-gradient-positioning.html

(3) Border radius artifact:
    fast/borders/border-radius-complex-inner.html

(4) Controls that don't look right (cut off buttons, misaligned sliders):
    fast/forms/control-clip-overflow.html
    fast/forms/input-appearance-height.html

 

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