Bugzilla

### Security Approval Request
* **How easily could an exploit be constructed based on the patch?**: The issue occurs when StorageObserver receives a notify after it has been shut down. Users don't have access to the ClearStorages method used in the test which exposed the issue, and this has not been seen during the regular shutdown sequence. It would probably be hard to exploit this from the content process.
* **Do comments in the patch, the check-in comment, or tests included in the patch paint a bulls-eye on the security problem?**: No
* **Which older supported branches are affected by this flaw?**: All
* **If not all supported branches, which bug introduced the flaw?**: None
* **Do you have backports for the affected branches?**: No
* **If not, how different, hard to create, and risky will they be?**: The changed parts of the code have not changed much recently so backports are not expected to be hard to create.
* **How likely is this patch to cause regressions; how much testing does it need?**: The change mainly clears an array at shutdown and adds more checks that our object is not used after shutdown. Regressions are unlikely as this is merely adding redundancy to guarantee the old functionality under special circumstances.

### Security Approval Request
* **How easily could an exploit be constructed based on the patch?**: The issue occurs when StorageObserver receives a notify after it has been shut down. Users don't have access to the ClearStorages method used in the test which exposed the issue, and this has not been seen during the regular shutdown sequence. It would probably be hard to exploit this from the content process.
* **Do comments in the patch, the check-in comment, or tests included in the patch paint a bulls-eye on the security problem?**: No
* **Which older supported branches are affected by this flaw?**: All
* **If not all supported branches, which bug introduced the flaw?**: None
* **Do you have backports for the affected branches?**: No
* **If not, how different, hard to create, and risky will they be?**: The relevant parts of the code have not changed much recently so backports are not expected to be hard to create.
* **How likely is this patch to cause regressions; how much testing does it need?**: The change mainly clears an array at shutdown and adds more checks that our object is not used after shutdown. Regressions are unlikely as this is merely adding redundancy to guarantee the old functionality under special circumstances.