This follows the documentation example:
* Scalar deserialization is started
* “test” scalar is incremented by “10” by the application -> The operation [test, add, 10] is recorded into the list.
* The state of the “test” scalar is loaded off the persistence file, and the value “14” is set.
* Deserialization is finished and the pending operations are applied.
* The “test” scalar is incremented by “10”, the value is now “24”
It does that in both the parent and the content process.
MozReview-Commit-ID: CnzDcJ5o7jJ
4abf3e3621