No editor consumer accesses this object from multiple threads. I'm not sure about places though...
The object is cycle collectable, so it would crash immediately if used in non-main-thread.
(In reply to Ehsan Akhgari [:ehsan] from comment #1) > No editor consumer accesses this object from multiple threads. I'm not sure > about places though... Places only uses the transaction manager from js in the ui thread.
Created attachment 585058 [details] [diff] [review] Patch (v1)
Try run for 6355fe761f05 is complete. Detailed breakdown of the results available here: https://tbpl.mozilla.org/?tree=Try&rev=6355fe761f05 Results (out of 206 total builds): exception: 1 success: 183 warnings: 22 Builds (or logs if builds failed) available at: http://email@example.com Timed out after 06 hours without completing.