[GCM] Track connection failures properly

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 "base/time/time.h"
 #include "google_apis/gcm/base/gcm_export.h"
 #include "google_apis/gcm/engine/connection_handler.h"
 
 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.
+    // Count of total number of connection reset reasons. All new reset reasons
+    // should be added above this line.
+    CONNECTION_RESET_COUNT,
+  };
+
   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 19 matching lines @@
 
   // 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() = 0;
+  virtual void SignalConnectionReset(ConnectionResetReason reason) = 0;
 };
 
 }  // namespace gcm
 
 #endif  // GOOGLE_APIS_GCM_ENGINE_CONNECTION_FACTORY_H_