Add IsSupportedBitstreamAudioCodec() function in MediaClient.

media/base/key_systems_unittest.cc

Index: media/base/key_systems_unittest.cc
diff --git a/media/base/key_systems_unittest.cc b/media/base/key_systems_unittest.cc
index 9eea5437dcfd70adf85253fd550bcfd4b2a4cac6..3a5d21bb5e5cb535e8e3e8fbdba1422d0fad156f 100644
--- a/media/base/key_systems_unittest.cc
+++ b/media/base/key_systems_unittest.cc
@@ -228,6 +228,7 @@ class TestMediaClient : public MediaClient {
                                   key_systems_properties) override;
   bool IsSupportedAudioConfig(const media::AudioConfig& config) final;
   bool IsSupportedVideoConfig(const media::VideoConfig& config) final;
+  bool IsSupportedBitstreamAudioCodec(AudioCodec codec) final;
 
   // Helper function to test the case where IsKeySystemsUpdateNeeded() is true
   // after AddSupportedKeySystems() is called.
@@ -273,6 +274,10 @@ bool TestMediaClient::IsSupportedVideoConfig(const media::VideoConfig& config) {
   return true;
 }
 
+bool TestMediaClient::IsSupportedBitstreamAudioCodec(AudioCodec codec) {
+  return false;
+}
+
 void TestMediaClient::SetKeySystemsUpdateNeeded() {
   is_update_needed_ = true;
 }