Change PeerConnectionFactoryForUsageHistogramTest to not inherit RefCountedObject

Bug: webrtc:12701
Change-Id: Icea3774c5c1acb6854e50116e7defaf4846c990f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/256684
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Niels Moller <nisse@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#36349}

pc/peer_connection_histogram_unittest.cc

diff --git a/pc/peer_connection_histogram_unittest.cc b/pc/peer_connection_histogram_unittest.cc
index ae88b65..cc87b6a 100644
--- a/pc/peer_connection_histogram_unittest.cc
+++ b/pc/peer_connection_histogram_unittest.cc
@@ -75,10 +75,10 @@
 }
 
 class PeerConnectionFactoryForUsageHistogramTest
-    : public rtc::RefCountedObject<PeerConnectionFactory> {
+    : public PeerConnectionFactory {
  public:
   PeerConnectionFactoryForUsageHistogramTest()
-      : rtc::RefCountedObject<PeerConnectionFactory>([] {
+      : PeerConnectionFactory([] {
           PeerConnectionFactoryDependencies dependencies;
           dependencies.network_thread = rtc::Thread::Current();
           dependencies.worker_thread = rtc::Thread::Current();
@@ -330,8 +330,8 @@
       const RTCConfiguration& config,
       const PeerConnectionFactoryInterface::Options factory_options,
       PeerConnectionDependencies deps) {
-    rtc::scoped_refptr<PeerConnectionFactoryForUsageHistogramTest> pc_factory(
-        new PeerConnectionFactoryForUsageHistogramTest());
+    auto pc_factory =
+        rtc::make_ref_counted<PeerConnectionFactoryForUsageHistogramTest>();
     pc_factory->SetOptions(factory_options);
 
     // If no allocator is provided, one will be created using a network manager