Prevent Google Mail Checker from scheduling more than one concurrent request.

In the case of failures (simulated by blackholing in /etc/hosts,
getInboxCount was calling onError in both the onreadystatechange and onerror
handlers). Prevent this in two ways: by only invoking the callback once and by
making scheduleRequest cancel any already-scheduled requests.


Review URL:

git-svn-id: svn:// 0039d316-1c4b-4281-b951-d872f2087c98
3 files changed