[GCM] Add connection/persistent store metric collection

google_apis/gcm/engine/connection_factory_impl.cc

 // Copyright (c) 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.
 
 #include "google_apis/gcm/engine/connection_factory_impl.h"
 
 #include "base/message_loop/message_loop.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/sparse_histogram.h"
 #include "google_apis/gcm/engine/connection_handler_impl.h"
 #include "google_apis/gcm/protocol/mcs.pb.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_request_headers.h"
 #include "net/proxy/proxy_info.h"
 #include "net/socket/client_socket_handle.h"
 #include "net/socket/client_socket_pool_manager.h"
 #include "net/ssl/ssl_config_service.h"
 
@@ skipping 186 matching lines @@
 
 scoped_ptr<net::BackoffEntry> ConnectionFactoryImpl::CreateBackoffEntry(
     const net::BackoffEntry::Policy* const policy) {
   return scoped_ptr<net::BackoffEntry>(new net::BackoffEntry(policy));
 }
 
 void ConnectionFactoryImpl::OnConnectDone(int result) {
   if (result != net::OK) {
     LOG(ERROR) << "Failed to connect to MCS endpoint with error " << result;
     backoff_entry_->InformOfRequest(false);
+    UMA_HISTOGRAM_SPARSE_SLOWLY("GCM.ConnectionFailureErrorCode", result);
     Connect();
     return;
   }
 
   DVLOG(1) << "MCS endpoint socket connection success, starting handshake.";
   InitHandler();
 }
 
 void ConnectionFactoryImpl::ConnectionHandlerCallback(int result) {
   if (result == net::OK) {
     // Handshake succeeded, reset the backoff.
     connecting_ = false;
     backoff_reset_time_ = base::TimeTicks::Now();
     previous_backoff_.swap(backoff_entry_);
     backoff_entry_->Reset();
     return;
   }
+
+  if (!connecting_)
+    UMA_HISTOGRAM_SPARSE_SLOWLY("GCM.ConnectionDisconnectErrorCode", result);
+
   // TODO(zea): Consider how to handle errors that may require some sort of
   // user intervention (login page, etc.).
   LOG(ERROR) << "Connection reset with error " << result;
   backoff_entry_->InformOfRequest(false);
   Connect();
 }
 
 }  // namespace gcm