Added ConnectionTimeObserver to calculate the times to authenticate and connect.

remoting/test/connection_time_observer.h

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef REMOTING_TEST_CONNECTION_TIME_OBSERVER_H_
+#define REMOTING_TEST_CONNECTION_TIME_OBSERVER_H_
+
+#include <map>
+
+#include "remoting/test/remote_connection_observer.h"
+
+namespace remoting {
+namespace test {
+
+// Observes and saves the times when TestChromotingClient changes its state. It

[joedow, 2015/07/23 16:57:55]

I don't think the comment should mention the TestChromotingClient, this
connection observer could be used for any class which creates a chromoting
connection and allows an observer to be attached.

[tonychun, 2015/07/24 01:41:47]

Good point. Thank you.

+// allows for tests to access latency times between the different states the
+// client was in.
+class ConnectionTimeObserver
+    : public RemoteConnectionObserver {
+ public:
+  ConnectionTimeObserver();
+  ~ConnectionTimeObserver() override;
+
+  // RemoteConnectionObserver interface.
+  void ConnectionStateChanged(protocol::ConnectionToHost::State state,
+                              protocol::ErrorCode error_code) override;
+
+  // Returns the delta time in milliseconds between |start_state| and
+  // |end_state| stored in |transition_times_map_|.
+  int GetStateTransitionDelay(

[Sergey Ulanov, 2015/07/23 19:20:57]

Return base::TimeDelta here?

[tonychun, 2015/07/24 01:41:47]

Done.

+      const protocol::ConnectionToHost::State& start_state,
+      const protocol::ConnectionToHost::State& end_state) const;
+
+ private:
+  // Saves the latest state the ChromotingClient is in.

[joedow, 2015/07/23 16:57:54]

Technically the state is provided by the ConnectionToHost class, not the
ChromotingClient (the client just pulls all of the connection pieces together,
it doesn't create the connection).  Simpler just to say that it represents the
current connection state of client to host.

[tonychun, 2015/07/24 01:41:47]

I've changed the name to current_connection_state_ to better reflect what it
means. I've also changed the comments.

+  protocol::ConnectionToHost::State current_state_ =
+      protocol::ConnectionToHost::State::INITIALIZING;
+
+  // Stores TimeTick of states the client changes to.
+  std::map<protocol::ConnectionToHost::State, base::TimeTicks>
+      transition_times_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(ConnectionTimeObserver);
+};
+
+}  // namespace test
+}  // namespace remoting
+
+#endif  // REMOTING_TEST_CONNECTION_TIME_OBSERVER_H_