Tests asynchronous call stacks for window.postMessage.

Set timer for test function.
Captured call stacks in no particular order:
Call stack:
    0) onMessageReceivedInFrame (post-message-listener.html:7)
    [postMessage]
    0) postMessageToFrame (async-callstack-post-message.js:44)
    1) onMessageReceivedInParent (async-callstack-post-message.js:32)
    [postMessage]
    0) postMessageToParent (post-message-listener.html:13)
    1) onMessageReceivedInFrame (post-message-listener.html:8)
    [postMessage]
    0) postMessageToFrame (async-callstack-post-message.js:44)
    1) timeout (async-callstack-post-message.js:25)
    [setTimeout]
    0) testFunction (async-callstack-post-message.js:18)
    [setTimeout]
    0) scheduleTestFunction <omitted>
    <... skipped remaining frames ...>

Call stack:
    0) onMessageReceivedInFrame (post-message-listener.html:7)
    [postMessage]
    0) postMessageToFrame (async-callstack-post-message.js:44)
    1) timeout (async-callstack-post-message.js:25)
    [setTimeout]
    0) testFunction (async-callstack-post-message.js:18)
    [setTimeout]
    0) scheduleTestFunction <omitted>
    <... skipped remaining frames ...>

Call stack:
    0) onMessageReceivedInParent (async-callstack-post-message.js:30)
    [postMessage]
    0) postMessageToParent (post-message-listener.html:13)
    1) onMessageReceivedInFrame (post-message-listener.html:8)
    [postMessage]
    0) postMessageToFrame (async-callstack-post-message.js:44)
    1) onMessageReceivedInParent (async-callstack-post-message.js:32)
    [postMessage]
    0) postMessageToParent (post-message-listener.html:13)
    1) onMessageReceivedInFrame (post-message-listener.html:8)
    [postMessage]
    0) postMessageToFrame (async-callstack-post-message.js:44)
    1) timeout (async-callstack-post-message.js:25)
    [setTimeout]
    0) testFunction (async-callstack-post-message.js:18)
    [setTimeout]
    0) scheduleTestFunction <omitted>
    <... skipped remaining frames ...>

Call stack:
    0) onMessageReceivedInParent (async-callstack-post-message.js:30)
    [postMessage]
    0) postMessageToParent (post-message-listener.html:13)
    1) onMessageReceivedInFrame (post-message-listener.html:8)
    [postMessage]
    0) postMessageToFrame (async-callstack-post-message.js:44)
    1) timeout (async-callstack-post-message.js:25)
    [setTimeout]
    0) testFunction (async-callstack-post-message.js:18)
    [setTimeout]
    0) scheduleTestFunction <omitted>
    <... skipped remaining frames ...>

Call stack:
    0) onMessageReceivedInParent (async-callstack-post-message.js:30)
    [postMessage]
    0) postMessageToSelf (async-callstack-post-message.js:37)
    1) timeout (async-callstack-post-message.js:24)
    [setTimeout]
    0) testFunction (async-callstack-post-message.js:18)
    [setTimeout]
    0) scheduleTestFunction <omitted>
    <... skipped remaining frames ...>