In older browsers such as IE10, inheritance of static properties on class
types is implemented by copying the properties. This makes hasOwnProperty
unreliable for checking if a static property is defined directly on a class
or is inherited. This causes problems when trying to read the
ngInjectableDef properties of inherited services, as in IE10 even inherited
definitions will appear to be local.
Instead, the 'token' property on ngInjectableDef can be leveraged to detect
when a definition is read which doesn't belong to the type itself.
PR Close#30855
b2937b16c3