Added ConnectionTimeObserver to calculate the times to authenticate and connect.

remoting/protocol/connection_to_host.h

 // Copyright (c) 2012 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_PROTOCOL_CONNECTION_TO_HOST_H_
 #define REMOTING_PROTOCOL_CONNECTION_TO_HOST_H_
 
 #include <string>
 
 #include "base/callback_forward.h"
+#include "base/logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "remoting/protocol/errors.h"
 
+#define RETURN_STRING_LITERAL(x) \
+case x: \
+return #x;

[joedow, 2015/07/29 17:07:02]

I'm personally not a fan of macros like this for a handful of returns, but I'll
leave this one up to you since Sergey suggested it.

[tonychun, 2015/07/29 18:30:33]

Done.

+
 namespace remoting {
 
 class SignalStrategy;
 
 namespace protocol {
 
 class AudioStub;
 class Authenticator;
 class CandidateSessionConfig;
 class ClientStub;
@@ skipping 32 matching lines @@
     // is set to false some data sent by the peers may be
     // delayed. This is used to indicate in the UI when connection is
     // temporarily broken.
     virtual void OnConnectionReady(bool ready) = 0;
 
     // Called when the route type (direct vs. STUN vs. proxied) changes.
     virtual void OnRouteChanged(const std::string& channel_name,
                                 const protocol::TransportRoute& route) = 0;
   };
 
+  static const char* ConnectionStateToFriendlyString(State state) {
+    switch (state) {
+      RETURN_STRING_LITERAL(INITIALIZING);
+      RETURN_STRING_LITERAL(CONNECTING);
+      RETURN_STRING_LITERAL(AUTHENTICATED);
+      RETURN_STRING_LITERAL(CONNECTED);
+      RETURN_STRING_LITERAL(CLOSED);
+      RETURN_STRING_LITERAL(FAILED);
+      default:
+        LOG(ERROR) << "Unknown connection state: '" << state << "'";
+        return "UNKNOWN";
+    }
+  }
+
   virtual ~ConnectionToHost() {}
 
   // Allows to set a custom protocol configuration (e.g. for tests). Cannot be
   // called after Connect().
   virtual void set_candidate_config(
       scoped_ptr<CandidateSessionConfig> config) = 0;
 
   // Set the stubs which will handle messages from the host.
   // The caller must ensure that stubs out-live the connection.
   // Unless otherwise specified, all stubs must be set before Connect()
@@ skipping 26 matching lines @@
   virtual InputStub* input_stub() = 0;
 
   // Return the current state of ConnectionToHost.
   virtual State state() const = 0;
 };
 
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_CONNECTION_TO_HOST_H_