Disable overlay scrollbars to hide them on non-Mac.

third_party/WebKit/LayoutTests/TestExpectations

 # Intentional failures to test the layout test system.
 Bug(intentional) [ Android Linux Win Mac10.10 Mac10.11 Retina ] harness-tests/crash.html [ Crash ]
 crbug.com/644303 [ Mac10.9 ] harness-tests/crash.html [ Crash Timeout ]
 Bug(intentional) harness-tests/timeout.html [ Timeout ]
 
 # ====== Oilpan-only failures from here ======
 # Most of these actually cause the tests to report success, rather than
 # failure. Expected outputs will be adjusted for the better once Oilpan
 # has been well and truly enabled always.
 
@@ skipping 873 matching lines @@
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-overried-inherited-visibility-hidden.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-scrolling-no-overried-inherited-visibility-hidden.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-scrolling-no-visibility-hidden-child.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-scrolling-no.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-scrolling-yes.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-visibility-hidden-child.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame-zero-size-and-border.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollable-area-frame.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollbar-tickmarks-styled.html [ Failure ]
 crbug.com/417782 virtual/rootlayerscrolls/fast/scrolling/scrollbar-tickmarks-styled-after-onload.html [ Failure ]
+crbug.com/417782 virtual/rootlayerscrolls/scrollbars/hidden-scrollbars-invisible.html [ Failure ]

[skobes, 2016/11/17 21:16:31]

Do you know why this fails?

[bokan, 2016/11/17 23:22:27]

I hadn't dug in deeply to find out the root cause but it looked like the clip is
applied in correctly to iframes for some reason. I assumed that was the reason
but on closer inspection there was more.

scrolling="no" on an iframe doesn't work. I disabled the scrollbars through
style so that did the trick. The only issue is now that it doesn't work because
the scrollingElement has overflow:auto which doesn't work but is fixed by the
follow up patch so I left this line in and removed it in the followup.

[skobes, 2016/11/17 23:54:58]

Ok, thanks for digging into it.

 
 crbug.com/651343 fast/text/international/inline-plaintext-relayout-with-leading-neutrals.html [ Pass Failure ]
 
 crbug.com/385014 crbug.com/410145 accessibility/canvas-fallback-content-2.html [ Pass Failure Timeout ]
 
 crbug.com/574283 [ Mac ] fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-anchors.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/scroll_customization/fast/scroll-behavior/smooth-scroll/ongoing-smooth-scroll-anchors.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/first-scroll-runs-on-compositor.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/fixed-background-in-iframe.html [ Skip ]
 crbug.com/574283 [ Mac ] virtual/threaded/fast/scroll-behavior/smooth-scroll/horizontal-smooth-scroll-in-rtl.html [ Skip ]
@@ skipping 688 matching lines @@
 crbug.com/657646 [ Win ] fast/text/font-stretch.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/sub-pixel/text-scaling-pixel.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/international/bidi-listbox-atsui.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/international/bidi-listbox.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/international/lang-glyph-cache-separation.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/font-stretch-variant.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/drawBidiText.html [ Failure Pass ]
 crbug.com/657646 [ Win ] fast/text/font-features/caps-native-synthesis.html [ Failure Pass ]
 
 crbug.com/664450 inspector/console/console-on-animation-worklet.html [ Skip ]