RTL execution highlight missing.

[NeilFraser]

Open the playground. Create one block. Execute in console:

Blockly.getMainWorkspace().getTopBlocks()[0].setHighlighted(true);

Result:

Now switch to RTL. Repeat. Result:

Found while testing a candidate release of Blockly Games.

[NeilFraser]

It's a browser bug. Chrome only, Firefox is ok. Creating minimal test case and filing bug with Chromium...

[NeilFraser]

Bug filed:
https://bugs.chromium.org/p/chromium/issues/detail?id=876446

[NeilFraser]

Chromium team claims that "Bisecting indicates that this never worked."
I find this hard to believe. We've been using execution highlighting for over a year.