[GCM] Add ConnectionListener support, and hook up to debug page

google_apis/gcm/engine/connection_factory.h

 // Copyright 2013 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 GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_H_
 #define GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_H_
 
+#include <string>
+
 #include "base/time/time.h"
 #include "google_apis/gcm/base/gcm_export.h"
 #include "google_apis/gcm/engine/connection_handler.h"
 
+class GURL;
+
+namespace net {
+class IPEndPoint;
+}
+
 namespace mcs_proto {
 class LoginRequest;
 }
 
 namespace gcm {
 
 // Factory for creating a ConnectionHandler and maintaining its connection.
 // The factory retains ownership of the ConnectionHandler and will enforce
 // backoff policies when attempting connections.
 class GCM_EXPORT ConnectionFactory {
  public:
   typedef base::Callback<void(mcs_proto::LoginRequest* login_request)>
       BuildLoginRequestCallback;
 
   // Reasons for triggering a connection reset. Note that these enums are
   // consumed by a histogram, so ordering should not be modified.
   enum ConnectionResetReason {
     LOGIN_FAILURE,      // Login response included an error.
     CLOSE_COMMAND,      // Received a close command.
     HEARTBEAT_FAILURE,  // Heartbeat was not acknowledged in time.
     SOCKET_FAILURE,     // net::Socket error.
     NETWORK_CHANGE,     // NetworkChangeNotifier notified of a network change.
     // Count of total number of connection reset reasons. All new reset reasons
     // should be added above this line.
     CONNECTION_RESET_COUNT,
   };
 
+  // Listener interface to be notified of endpoint connection events.
+  class GCM_EXPORT ConnectionListener {
+   public:
+    ConnectionListener();
+    virtual ~ConnectionListener();
+
+    // Notifies the listener that GCM has performed a handshake with and is now
+    // actively connected to |current_server|. |ip_endpoint| is the resolved
+    // ip address/port through which the connection is being made.
+    virtual void OnConnected(const GURL& current_server,
+                             const net::IPEndPoint& ip_endpoint) = 0;
+
+    // Notifies the listener that the connection has been interrupted.
+    virtual void OnDisconnected() = 0;
+  };
+
   ConnectionFactory();
   virtual ~ConnectionFactory();
 
   // Initialize the factory, creating a connection handler with a disconnected
   // socket. Should only be called once.
   // Upon connection:
   // |read_callback| will be invoked with the contents of any received protobuf
   // message.
   // |write_callback| will be invoked anytime a message has been successfully
   // sent. Note: this just means the data was sent to the wire, not that the
@@ skipping 10 matching lines @@
   // Opens a new connection and initiates login handshake. Upon completion of
   // the handshake, |read_callback| will be invoked with a valid
   // mcs_proto::LoginResponse.
   // Note: Initialize must have already been invoked.
   virtual void Connect() = 0;
 
   // Whether or not the MCS endpoint is currently reachable with an active
   // connection.
   virtual bool IsEndpointReachable() const = 0;
 
+  // Returns a debug string describing the connection state.
+  virtual std::string GetConnectionStateString() const = 0;
+
   // If in backoff, the time at which the next retry will be made. Otherwise,
   // a null time, indicating either no attempt to connect has been made or no
   // backoff is in progress.
   virtual base::TimeTicks NextRetryAttempt() const = 0;
 
   // Manually reset the connection. This can occur if an application specific
   // event forced a reset (e.g. server sends a close connection response).
   // If the last connection was made within kConnectionResetWindowSecs, the old
   // backoff is restored, else a new backoff kicks off.
   virtual void SignalConnectionReset(ConnectionResetReason reason) = 0;
+
+  // Sets the current connection listener. Only one listener is supported at a
+  // time, and the listener must either outlive the connection factory or
+  // call SetConnectionListener(NULL) upon destruction.
+  virtual void SetConnectionListener(ConnectionListener* listener) = 0;
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_H_