The $locationShim has onChange listeners to allow for synchronization logic between
AngularJS and Angular. When the AngularJS routing events are emitted first, this can
cause Angular code to be out of sync. Notifying the listeners earlier solves the
problem.
PR Close#32037
The LocationShim (replacement for `$location`) was added to centralize dealing with the browser URL. Additionally, an `onUrlChange` method was added to Angular's Location service. This PR adds a corresponding method to the LocationShim so updates from AngularJS can be tracked in Angular.
PR Close#30466