WebXR Content Broken in Chrome in Android 12

[peka7777777]

When opening any of the demos on my Android 12 device in Chrome/Canary (Pixel 4a, Android 12, build SP1A.210812.015) I get the following crash in logcat and the app hard crashes -

10-21 13:49:26.416 18396 18396 W System.err: java.lang.IllegalArgumentException: com.android.chrome: Targeting S+ (version 31 and above) requires that one of FLAG_IMMUTABLE or FLAG_MUTABLE be specified when creating a PendingIntent.
10-21 13:49:26.416 18396 18396 W System.err: Strongly consider using FLAG_IMMUTABLE, only use FLAG_MUTABLE if some functionality depends on the PendingIntent being mutable, e.g. if it needs to be used with inline replies or bubbles.
10-21 13:49:26.416 18396 18396 W System.err: at android.app.PendingIntent.checkFlags(PendingIntent.java:375)
10-21 13:49:26.416 18396 18396 W System.err: at android.app.PendingIntent.getBroadcastAsUser(PendingIntent.java:645)
10-21 13:49:26.416 18396 18396 W System.err: at android.app.PendingIntent.getBroadcast(PendingIntent.java:632)
10-21 13:49:26.416 18396 18396 W System.err: at org.chromium.chrome.browser.vr.VrShellDelegate.q(chromium-TrichromeChromeGoogle.aab-stable-460608533:10)
10-21 13:49:26.416 18396 18396 W System.err: at org.chromium.chrome.browser.vr.VrShell.(chromium-TrichromeChromeGoogle.aab-stable-460608533:60)
10-21 13:49:26.416 18396 18396 W System.err: at org.chromium.chrome.browser.vr.VrShellDelegate.j(chromium-TrichromeChromeGoogle.aab-stable-460608533:9)
10-21 13:49:26.416 18396 18396 W System.err: at org.chromium.chrome.browser.vr.VrShellDelegate.n(chromium-TrichromeChromeGoogle.aab-stable-460608533:6)
10-21 13:49:26.416 18396 18396 W System.err: at org.chromium.chrome.browser.vr.VrShellDelegate.p(chromium-TrichromeChromeGoogle.aab-stable-460608533:10)
10-21 13:49:26.416 18396 18396 W System.err: at org.chromium.chrome.browser.vr.VrShellDelegate.presentRequested(chromium-TrichromeChromeGoogle.aab-stable-460608533:4)
10-21 13:49:26.416 18396 18396 W System.err: at android.os.MessageQueue.nativePollOnce(Native Method)
10-21 13:49:26.416 18396 18396 W System.err: at android.os.MessageQueue.next(MessageQueue.java:335)
10-21 13:49:26.416 18396 18396 W System.err: at android.os.Looper.loopOnce(Looper.java:161)
10-21 13:49:26.416 18396 18396 W System.err: at android.os.Looper.loop(Looper.java:288)
10-21 13:49:26.416 18396 18396 W System.err: at android.app.ActivityThread.main(ActivityThread.java:7842)
10-21 13:49:26.416 18396 18396 W System.err: at java.lang.reflect.Method.invoke(Native Method)
10-21 13:49:26.416 18396 18396 W System.err: at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:548)
10-21 13:49:26.416 18396 18396 W System.err: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1003)
10-21 13:49:26.417 18396 18396 F chromium: [FATAL:jni_android.cc(306)] Please include Java exception stack in crash report

[vincentfretin]

I just saw the discussion on slack where you provided the link to the chromium issue you created and see you didn't put it there, so here it is:
https://bugs.chromium.org/p/chromium/issues/detail?id=1262111