Tests asynchronous call stacks for DataTransferItem.getAsString.
Set timer for test function.
Captured call stacks in no particular order:
Call stack:
0) onGetAsString (async-callstack-get-as-string.js:46)
[DataTransferItem.getAsString]
0) onPaste (async-callstack-get-as-string.js:41)
1) timeout (async-callstack-get-as-string.js:32)
[setTimeout]
0) testFunction (async-callstack-get-as-string.js:17)
[setTimeout]
0) scheduleTestFunction <omitted>
<... skipped remaining frames ...>
Call stack:
0) onPaste (async-callstack-get-as-string.js:37)
1) timeout (async-callstack-get-as-string.js:32)
[setTimeout]
0) testFunction (async-callstack-get-as-string.js:17)
[setTimeout]
0) scheduleTestFunction <omitted>
<... skipped remaining frames ...>