We have the following rule in chromium_apk.flags:
-keepnames class * implements android.os.Parcelable

And within chromium_code.flags we have:
-keepnames class org.chromium.** implements android.os.Parcelable

Links:
https://cs.chromium.org/chromium/src/base/android/proguard/chromium_apk.flags?type=cs&q=file:flags+android.os.Parcelable&sq=package:chromium&l=19

https://cs.chromium.org/chromium/src/base/android/proguard/chromium_code.flags?type=cs&q=file:flags+android.os.Parcelable&sq=package:chromium&l=58

The first one is overly broad and can likely be removed.

The second one we can wait on investigating until after we enable renaming for org.chromium anyways.