Added ConnectionTimeObserver to calculate the times to authenticate and connect.

remoting/test/chromoting_connection_observer.h

+// Copyright 2015 The Chromium Authors. All rights reserved.

[joedow, 2015/07/20 16:30:58]

Is it intentional that you have not added this to any build files or unit tests?
 This seems like a partial CL.

[tonychun, 2015/07/20 17:49:59]

This is a partial CL. Once my changes for environment and connecting to
localhost land, I will continue to add this change.

+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_TEST_CHROMOTING_CONNECTION_OBSERVER_H_
+#define REMOTING_TEST_CHROMOTING_CONNECTION_OBSERVER_H_
+
+#include <map>
+
+#include "remoting/test/remote_connection_observer.h"
+
+namespace remoting {
+namespace test {
+
+// Observes and calculates the time between each state change of the chromoting
+// connection process.
+class ChromotingConnectionObserver

[joedow, 2015/07/20 16:30:58]

I would probably just call this class a connection time observer.

[tonychun, 2015/07/20 17:49:59]

Done.

+    : public RemoteConnectionObserver {
+ public:
+  ChromotingConnectionObserver();
+  ~ChromotingConnectionObserver() override;
+
+  // RemoteConnectionObserver interface.
+  void ConnectionStateChanged(protocol::ConnectionToHost::State state,
+                              protocol::ErrorCode error_code) override;
+  void ConnectionReady(bool ready) override;
+  void RouteChanged(const std::string& channel_name,
+                    const protocol::TransportRoute& route) override;
+  void CapabilitiesSet(const std::string& capabilities) override;
+  void PairingResponseSet(
+    const protocol::PairingResponse& pairing_response) override;
+  void HostMessageReceived(const protocol::ExtensionMessage& message) override;
+
+ private:
+  // Used to convert connection states to strings.
+  std::map<protocol::ConnectionToHost::State, std::string> state_map_;
+
+  // Saves the latest state the ChromotingClient is in.
+  protocol::ConnectionToHost::State current_state_;
+
+  // Used to find the time difference between subsequent calls to
+  // ConnectionStateChanged.
+  base::TimeTicks delta_;

[joedow, 2015/07/20 16:30:58]

I think this var should be renamed as delta_ isn't very descriptive. 
last_state_change_time_ticks would be more clear.

[tonychun, 2015/07/20 17:49:59]

Done.

+
+  DISALLOW_COPY_AND_ASSIGN(ChromotingConnectionObserver);
+};
+
+}  // namespace test
+}  // namespace remoting
+
+#endif  // REMOTING_TEST_CHROMOTING_CONNECTION_OBSERVER_H_