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;
+
 namespace remoting {
 
 class SignalStrategy;
 
 namespace protocol {
 
 class AudioStub;
 class Authenticator;
 class CandidateSessionConfig;
 class ClientStub;
@@ skipping 74 matching lines @@
 
   // Stubs for sending data to the host.
   virtual ClipboardStub* clipboard_forwarder() = 0;
   virtual HostStub* host_stub() = 0;
   virtual InputStub* input_stub() = 0;
 
   // Return the current state of ConnectionToHost.
   virtual State state() const = 0;
 };
 
+inline const char* ConnectionStateToString(ConnectionToHost::State state) {

[joedow, 2015/07/29 20:09:31]

I'd remove the inline here.  This function is called for debugging or displaying
nice error messages and isn't performance critical so it is more likely to bloat
the code than speed it up.

+  switch (state) {
+    RETURN_STRING_LITERAL(ConnectionToHost::INITIALIZING);
+    RETURN_STRING_LITERAL(ConnectionToHost::CONNECTING);
+    RETURN_STRING_LITERAL(ConnectionToHost::AUTHENTICATED);
+    RETURN_STRING_LITERAL(ConnectionToHost::CONNECTED);
+    RETURN_STRING_LITERAL(ConnectionToHost::CLOSED);
+    RETURN_STRING_LITERAL(ConnectionToHost::FAILED);
+    default:
+      LOG(ERROR) << "Unknown connection state: '" << state << "'";
+      return "ConnectionToHost::UNKNOWN";
+  }
+}
+
 }  // namespace protocol
 }  // namespace remoting
 
 #endif  // REMOTING_PROTOCOL_CONNECTION_TO_HOST_H_