Looks like a WebRender OOM that showed up in the 20210618092056 build. I'm assuming that it is probably a signature shift, but who knows maybe it isn't.
Here's the changelog for build 20210618092056:
There were four WebRender changes in that build:
Bug 1715515 - Part 1. Switch Windows 32 and mingwclang tests to WebRender.
Bug 1459526 - Handle full-range video in Webrender.
Bug 1717028 - Fix webrender render target debug view.
Bug 1716971 - Enable webrender on Android on NVIDIA Tegra GPUs.
All of these crashes are on Windows, so the Android bug is probably not relevant. All of these crashes are on amd64, so the Windows 32-bit test bug is probably not relevant.
There is also a bug related to graphics memory pressure, which might be related since this bug is about WebRender OOMs:
Bug 1716579 - Minimize memory usage of windows that haven't been rendered for a long time. r=gfx-reviewers,bradwerth