Remove the useless ACMTest base class

Bug: webrtc:8396
Change-Id: I021a2429910b21ffe4829e0ed51b9290bc715c0c
Reviewed-on: https://webrtc-review.googlesource.com/102884
Reviewed-by: Niels Moller <nisse@webrtc.org>
Commit-Queue: Karl Wiberg <kwiberg@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24907}
diff --git a/modules/audio_coding/test/PacketLossTest.h b/modules/audio_coding/test/PacketLossTest.h
index f6f92db..6018301 100644
--- a/modules/audio_coding/test/PacketLossTest.h
+++ b/modules/audio_coding/test/PacketLossTest.h
@@ -53,7 +53,7 @@
   int expected_loss_rate_;
 };
 
-class PacketLossTest : public ACMTest {
+class PacketLossTest {
  public:
   PacketLossTest(int channels,
                  int expected_loss_rate_,