Remove dependency on AudioStub in ConnectionToClient

remoting/host/chromoting_host_unittest.cc

Index: remoting/host/chromoting_host_unittest.cc
diff --git a/remoting/host/chromoting_host_unittest.cc b/remoting/host/chromoting_host_unittest.cc
index 315a15e3105f3fa4974b4ee7029f41d55cd6e6f6..4a0bdb933ba9221977111991a2f7cdd683a84223 100644
--- a/remoting/host/chromoting_host_unittest.cc
+++ b/remoting/host/chromoting_host_unittest.cc
@@ -127,8 +127,7 @@ class ChromotingHostTest : public testing::Test {
         (connection_index == 0) ? owned_connection1_ : owned_connection2_);
     protocol::ConnectionToClient* connection_ptr = connection.get();
     std::unique_ptr<ClientSession> client(new ClientSession(
-        host_.get(), task_runner_ /* audio_task_runner */,
-        std::move(connection), desktop_environment_factory_.get(),
+        host_.get(), std::move(connection), desktop_environment_factory_.get(),
         base::TimeDelta(), nullptr, std::vector<HostExtension*>()));
     ClientSession* client_ptr = client.get();