Remove obsolete TODO about future tracking

All futures need to be tracked so we can determine whether the set of
events is empty.

Fixed: dawn:2049
No-Try: true
Change-Id: Icbaf4d56c34cacb29ceed8586b446c230846d89e
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/192925
Auto-Submit: Austin Eng <enga@chromium.org>
Reviewed-by: Loko Kung <lokokung@google.com>
Commit-Queue: Loko Kung <lokokung@google.com>

src/dawn/native/EventManager.h

diff --git a/src/dawn/native/EventManager.h b/src/dawn/native/EventManager.h
index 0946708..a53f47d 100644
--- a/src/dawn/native/EventManager.h
+++ b/src/dawn/native/EventManager.h
@@ -57,8 +57,6 @@
 // There are various ways to optimize ProcessEvents/WaitAny:
 // - TODO(crbug.com/dawn/2059) Spontaneously set events as "early-ready" in other places when we see
 //   serials advance, e.g. Submit, or when checking a later wait before an earlier wait.
-// - TODO(crbug.com/dawn/2049) For thread-driven events (async pipeline compilation and Metal queue
-//   events), defer tracking for ProcessEvents until the event is already completed.
 class EventManager final : NonMovable {
   public:
     EventManager();