Ensure XMLDocumentParser doesn't hit a nullptr isolate while parsing a fragment
Bug: 376320342
Change-Id: I2be68f5bab0158121abf82aea1f5b6b71fab585c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6003358
Auto-Submit: Nate Chapin japhet@chromium.org
Reviewed-by: Joey Arhar jarhar@chromium.org
Commit-Queue: Joey Arhar jarhar@chromium.org
Commit-Queue: Nate Chapin japhet@chromium.org
Cr-Commit-Position: refs/heads/main@{#1379994}