Remove done item from TODO.

TODO.md

@@ -11,34 +11,3 @@ Javascript are converted to raw C strings for use with DTrace.
 With support for dynamic types and translators from the host DTrace
 implementation, it'd be possible to provide a mapping from Javascript
 objects to C structs, which could then be inspected in D scripts.
-
-## PERFORMANCE
-
-### Disabled Probe Effect
-
-The main problem here is how much work needs to be done to get to the
-point we can use the is-enabled check.
-
-While the is-enabled check allows us to avoid invoking the probe-args
-callback with its potentially expensive args-gathering work, we still
-do the following when a disabled probe is fired:
-
- * Dispatch Fire method from JS
- * Obtain DTraceProvider instance from V8 context
- * Args checking (must get a probe name and a callback)
- * Linear search through provider's probes for probe name
- * Invoke the is-enabled stub
-
-The fix I'd like to make here is to allow probes to exist as JS
-functions themselves, so that the calling code can directly invoke the
-function to fire the probe, avoiding the search by name. In this
-situation we could also defer checking the arguments until the probe
-is actually fired.
-
-With these changes, the disabled-probe overhead should be reduced to a
-JS method call, and then the invocation of the is-enabled stub.
-
-The API change to support this would be to return these probe
-functions from provider.addProbe(), rather than calling through
-provider.fire(), though that could easily remain for backwards
-compatibility.