angular/angular — pull request #277 by vicb (2014-12-04 09:52:26+00:00)
Title: perf(RecordRange): optimize disable()

There could be no lastEnabledChildRecord when there is no
firstEnabledChildRecord
- saves time by skipping findLastEnabledRecord() when the result is know
to be null,
- saves a test as isPresent(lastEnabledChildRecord) ==
isPresent(firstEnabledChildRecord)

/cc @rkirov @vsavkin