Remove use_drfuzz.

Nothing sets it, and it depended on Dr. Memory, which we removed
a while ago.

Depends on https://webrtc-review.googlesource.com/c/src/+/128222/

TBR=vasilii

Bug: 566930,655521
Change-Id: Ifab2f0951a1c954e0efa7206611f7b823e7c0867
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1527323
Commit-Queue: Nico Weber <thakis@chromium.org>
Reviewed-by: Jonathan Metzman <metzman@chromium.org>
Auto-Submit: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#641605}

diff --git a/BUILD.gn b/BUILD.gn
index fc8c50c..6cc7dae 100644
--- a/BUILD.gn
+++ b/BUILD.gn

@@ -722,8 +722,8 @@
     }
   }
 
-  if ((is_linux && !is_chromecast) ||
-      (is_win && (use_drfuzz || use_libfuzzer)) || (use_libfuzzer && is_mac)) {
+  if ((is_linux && !is_chromecast) || (is_win && use_libfuzzer) ||
+      (use_libfuzzer && is_mac)) {
     deps += [
       "//chrome/services/cups_ipp_parser/public/cpp:fuzzers",
       "//testing/libfuzzer/fuzzers",