Delete TODO that's done.

https://chromium-review.googlesource.com/706280 resolved it.

Bug: none
Change-Id: Ifedb80be1c3a8ad2af17552e024d7b6e0228ff03
Reviewed-on: https://chromium-review.googlesource.com/1187198Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#585590}

third_party/instrumented_libraries/BUILD.gn

@@ -57,8 +57,6 @@ if (prebuilt_instrumented_libraries_available) {
     }
   }
 
-  # TODO(GYP): scripts/download_binaries.py uses GYP_DEFINES to decide whether
-  # to download the archives extracted here.
   # Note: This requires a clobber whenever Ubuntu version changes.
   action("extract_prebuilt_instrumented_libraries") {
     visibility = [ ":prebuilt" ]