REGRESSION(r217118): Speedometer 2.0: Flight.js test is broken

REGRESSION(r217118): Speedometer 2.0: Flight.js test is broken
https://bugs.webkit.org/show_bug.cgi?id=172394

Reviewed by Chris Dumez.

PerformanceTests:

Fixed the bug that we were never clearing window.checkLoadedTimeoutId.

* Speedometer/resources/todomvc/dependency-examples/flight/flight/node_modules/requirejs/require.js:
(newContext.checkLoaded):

Websites/browserbench.org:

Merge the fix.

* Speedometer2.0/resources/todomvc/dependency-examples/flight/flight/node_modules/requirejs/require.js:
(newContext.checkLoaded):

git-svn-id: https://svn.webkit.org/repository/webkit/trunk@217161 268f45cc-cd09-0410-ab3c-d52691b4dbfc