Use correct thread for audio capturing and encoding.

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 cf7aa2493e0328ff0c7113745f4fcf51b4744845..6333e24f9d1dccf5512ae0fad8d270a4b3ae50b8 100644
--- a/remoting/host/chromoting_host_unittest.cc
+++ b/remoting/host/chromoting_host_unittest.cc
@@ -145,6 +145,7 @@ class ChromotingHostTest : public testing::Test {
         &signal_strategy_,
         desktop_environment_factory_.get(),
         scoped_ptr<protocol::SessionManager>(session_manager_),
+        context_.audio_task_runner(),
         context_.capture_task_runner(),
         context_.encode_task_runner(),
         context_.network_task_runner());
@@ -251,6 +252,7 @@ class ChromotingHostTest : public testing::Test {
     protocol::ConnectionToClient* connection_ptr = connection.get();
     scoped_refptr<ClientSession> client = new ClientSession(
         host_.get(),
+        context_.audio_task_runner(),
         context_.capture_task_runner(),
         context_.encode_task_runner(),
         context_.network_task_runner(),