The bugs appears to be due to rendering problems with scrolling a div that contains a fixed position element. If I change the fixed position element (#scenes) to be absolute, it suddenly works perfectly again. I think it also requires large amount of content in the DOM and probably other factors, but I am pretty confident based on testing that all the redraw problems go away if I change #scenes position to absolute in the Developer Tools, then they immediately come back when I change it back to fixed position.

I tracked it down further - the bug only reproduces if the position:fixed element (#scenes) is *before* the DOM element with the huge amount of contenteditable text, #editor_content. If I put it directly after (still within the same wrapper), apparently that fixes the issue entirely.

So the bug is actually fixed on our site. If someone cares, I will talk them through and show them the issue, but I have a suspicion it would've been hard to reproduce even if I left the code there. I am quite confident it is some flawed algorithm in the Chrome rendering algorithm related to fixed position, and having large amounts of non-fixed data after it (in the same wrapper), since moving the fixed position div to *after* the large amounts of data solved it.

Glad to hear that you worked out the problem.

Assigning to ccameron@ in case he wants to follow up - we've had some flashing content issues on Mac recently, although this sounds like it might be related to layout. 

ccameron: Feel free to close if you don't want to follow up.

I have more info: it was not the order precisely that mattered, it was the z-index (which implicitly changed when I swapped the order). When I left the position:fixed element #scenes after (which fixed it initially) *but* changed #scenes z-index to smaller (so it was like it was before, when I filed this) the issue immediately came back. So the bug seems to have to do with z-index of position:fixed elements being *smaller* than some other content, presumably related to a huge number of DOM elements. It's really easy for me to reproduce on my computer, so if you set up a time, I will be happy to screen-share and you may be able to reproduce it on your computer as well. It's a pretty horrendous bug, since it makes the browser feel like it's breaking, as if there's an earthquake in your computer. ;-)

Moving to Layout/3D.

This is worked around for now.

For me, there is frequent flickering while I scroll the page.
Ubuntu 16.04, 
Google Chrome	54.0.2840.100 (Official Build) (64-bit)
Revision	ed651c97177b2ac846b27f62bb8efed6dac0f90b-refs/branch-heads/2840@{#833}
OS	Linux 
JavaScript	V8 5.4.500.41
Flash	23.0.0.207
User Agent	Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/54.0.2840.100 Safari/537.36
Command Line	/usr/bin/google-chrome-stable --wm-user-time-ms=97146 --flag-switches-begin --enable-password-generation --flag-switches-end --disable_transparent_visuals --window-depth=24 --x11-visual-id=32
Executable Path	/opt/google/chrome/google-chrome

This issue has been Available for over a year. If it's no longer important or seems unlikely to be fixed, please consider closing it out. If it is important, please re-triage the issue.

Sorry for the inconvenience if the bug really should have been left as Available.

For more details visit https://www.chromium.org/issue-tracking/autotriage - Your friendly Sheriffbot

Closing this due to the workaround and long time from filing.

If the issue in Comment #6 persists, please file a separate bug with specific content that fails.