This patch adds two additional fields to each mscom log entry: The first is
the duration, in microseconds, of time spent in mscom overhead when executing
a call from the MTA on behalf of a remote client.
The second field is the duration, in microseconds, of time spent actually
executing the method within Gecko itself.
(In other words, the sum of the two fields will equal the total duration of
time spent executing the call.)
MozReview-Commit-ID: EhFieEPrhE5