docs(migration.ngdoc): add missing breaking changes from #16476

Closes #16557

docs/content/guide/migration.ngdoc

@@ -364,6 +364,58 @@ Where now the `oldValue` will always equal the previous `newValue`:
 |  `a=b=3` | [3, 2] | [1, 2] |
 
 
+#### **$interval**
+
+**Due to [a8bef9](https://github.com/angular/angular.js/commit/a8bef95127775d83d80daa4617c33227c4b443d4)**,
+`$interval.cancel() will throw an error if called with a promise that was not generated by
+`$interval()`. Previously, it would silently do nothing.
+
+Before:
+```js
+var promise = $interval(doSomething, 1000, 5).then(doSomethingElse);
+$interval.cancel(promise);  // No error; interval NOT canceled.
+```
+
+After:
+```js
+var promise = $interval(doSomething, 1000, 5).then(doSomethingElse);
+$interval.cancel(promise);  // Throws error.
+```
+
+Correct usage:
+```js
+var promise = $interval(doSomething, 1000, 5);
+var newPromise = promise.then(doSomethingElse);
+$interval.cancel(promise);  // Interval canceled.
+```
+
+
+#### **$timeout**
+
+**Due to [336525](https://github.com/angular/angular.js/commit/3365256502344970f86355d3ace1cb4251ae9828)**,
+`$timeout.cancel() will throw an error if called with a promise that was not generated by
+`$timeout()`. Previously, it would silently do nothing.
+
+Before:
+```js
+var promise = $timeout(doSomething, 1000).then(doSomethingElse);
+$timeout.cancel(promise);  // No error; timeout NOT canceled.
+```
+
+After:
+```js
+var promise = $timeout(doSomething, 1000).then(doSomethingElse);
+$timeout.cancel(promise);  // Throws error.
+```
+
+Correct usage:
+```js
+var promise = $timeout(doSomething, 1000);
+var newPromise = promise.then(doSomethingElse);
+$timeout.cancel(promise);  // Timeout canceled.
+```
+
+
 #### **$cookies**
 **Due to [73c646](https://github.com/angular/angular.js/commit/73c6467f1468353215dc689c019ed83aa4993c77)**,
 the `$cookieStore`service has been removed. Migrate to the $cookies service. Note that