Migrate from Duration Events to Complete Events

[saphal1998]

Feature request

The migration of Duration events to Complete events would be extremely useful here, as they essentially capture the same information in half the file size.

Why it is needed

For more context, please read the Complete Events section of Trace Event Format Document. Theoretically, this should reduce the file size by a factor of 2 🎉

Possible implementation

Keeping track of current and last active nodes, we can clearly determine all the events that are starting and ending at a particular timestamp.

A way to implement this would be to add all the start events (along with their timestamp of starting) in a hashMap, and only add the chrome events object after they have completed (duration can be obtained by subtracting end/current and start timestamps)