Make "Locate File" trigger when data loads if the user typed/pasted real fast

Summary:
Fixes T12599. If you're faster than the network request, we don't actually resolve your query when the data arrives.

Instead, when the data shows up, run the query if the user has typed something.

Test Plan: Pasted a filename in real fast, got results. (Previously: no results until you press something else.)

Reviewers: amckinley

Reviewed By: amckinley

Maniphest Tasks: T12599

Differential Revision: https://secure.phabricator.com/D17739