google/tracing-framework — pull request #74 by benvanik (2012-12-07 22:04:35+00:00)
Title: Adding the ability to add data to a scope after it is entered.

One of the wtf.trace.appendScopeData* methods can be used to add a key/value or, much more optimally, a custom appending function can be created to do this.

The UI will show the appended data along with any args that were passed to the scope, overriding any with the same name. This makes it much easier to add data to scopes that were auto-instrumented or where the data is not available when the scope is entered.