Bug 1567170 - Avoid thread leak in media fuzzing target. r=jya

Differential Revision: https://phabricator.services.mozilla.com/D41719

--HG--
extra : moz-landing-system : lando

dom/media/fuzz/FuzzMedia.cpp

@@ -18,6 +18,8 @@
 
 using namespace mozilla;
 
+RefPtr<SharedThreadPool> sFuzzThreadPool;
+
 class FuzzRunner {
  public:
   explicit FuzzRunner(Benchmark* aBenchmark) : mBenchmark(aBenchmark) {}
@@ -35,7 +37,9 @@ class FuzzRunner {
 };
 
 static int FuzzingInitMedia(int* argc, char*** argv) {
-  /* Generic no-op initialization used for all targets */
+  // Grab a strong reference to the media thread pool to avoid thread
+  // leaks. For more information, see bug 1567170.
+  sFuzzThreadPool = GetMediaThreadPool(MediaThreadType::PLAYBACK);
   return 0;
 }