[GCM] Handling connection events in GCMAccountTracker

components/gcm_driver/gcm_driver.cc

 // Copyright 2014 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 "components/gcm_driver/gcm_driver.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
@@ skipping 133 matching lines @@
     return;
   }
 
   SendCallback callback = callback_iter->second;
   send_callbacks_.erase(callback_iter);
   callback.Run(message_id, result);
 }
 
 void GCMDriver::Shutdown() {
   for (GCMAppHandlerMap::const_iterator iter = app_handlers_.begin();
-       iter != app_handlers_.end(); ++iter) {
-    iter->second->ShutdownHandler();
+       iter != app_handlers_.end();) {

[fgorski, 2014/10/03 18:03:32]

Jian Li, what do you think about this update?

+    DVLOG(1) << "Calling ShutdownHandler for: " << iter->first;
+    GCMAppHandler* handler = iter->second;
+    // Incrementing here, to make sure calls to RemoveAppHandler from
+    // ShutdownHandler don't invalidate the iterator.
+    ++iter;
+    handler->ShutdownHandler();
   }
   app_handlers_.clear();
 }
 
 void GCMDriver::AddAppHandler(const std::string& app_id,
                               GCMAppHandler* handler) {
   DCHECK(!app_id.empty());
   DCHECK(handler);
   DCHECK_EQ(app_handlers_.count(app_id), 0u);
   app_handlers_[app_id] = handler;
+  DVLOG(1) << "App handler added for: " << app_id;
 }
 
 void GCMDriver::RemoveAppHandler(const std::string& app_id) {
   DCHECK(!app_id.empty());
   app_handlers_.erase(app_id);
+  DVLOG(1) << "App handler removed for: " << app_id;
 }
 
 GCMAppHandler* GCMDriver::GetAppHandler(const std::string& app_id) {
   // Look for exact match.
   GCMAppHandlerMap::const_iterator iter = app_handlers_.find(app_id);
   if (iter != app_handlers_.end())
     return iter->second;
 
   // Ask the handlers whether they know how to handle it.
   for (iter = app_handlers_.begin(); iter != app_handlers_.end(); ++iter) {
@@ skipping 13 matching lines @@
   unregister_callbacks_.clear();
   send_callbacks_.clear();
 }
 
 bool GCMDriver::IsAsyncOperationPending(const std::string& app_id) const {
   return register_callbacks_.find(app_id) != register_callbacks_.end() ||
          unregister_callbacks_.find(app_id) != unregister_callbacks_.end();
 }
 
 }  // namespace gcm