Angular JS framework patched with https://www.npmjs.com/package/webkit-assign
The webkit-assign patch is related to the following issues affecting some versions of webkit in iOS:
From my understanding the error that occurs in the Angular code seems to be related to it's code using the following syntax:
var someObj = Object.create(Object.prototype); someObj.$$someAttr = someValue;
where someObj is created by Object.create, and the JIT in webkit (iOS 8), randomly generates an object with readonly properties.