DevTools: a better fix for socket closure crash.

chrome/browser/debugger/devtools_http_protocol_handler.cc

 // Copyright (c) 2010 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 "chrome/browser/debugger/devtools_http_protocol_handler.h"
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/message_loop_proxy.h"
 #include "base/string_number_conversions.h"
@@ skipping 245 matching lines @@
     return;
   }
 
   manager->ForwardToDevToolsAgent(
       it->second,
       DevToolsAgentMsg_DispatchOnInspectorBackend(data));
 }
 
 void DevToolsHttpProtocolHandler::OnCloseUI(HttpListenSocket* socket) {
   SocketToClientHostMap::iterator it = socket_to_client_host_ui_.find(socket);
-  if (it == socket_to_client_host_ui_.end())
-    return;
-  DevToolsClientHostImpl* client_host =
-      static_cast<DevToolsClientHostImpl*>(it->second);
-  client_host->NotifyCloseListener();
-  delete client_host;
-  socket_to_client_host_ui_.erase(socket);
+  if (it != socket_to_client_host_ui_.end()) {
+    DevToolsClientHostImpl* client_host =
+        static_cast<DevToolsClientHostImpl*>(it->second);
+    client_host->NotifyCloseListener();
+    delete client_host;
+    socket_to_client_host_ui_.erase(socket);
+  }
 
   // We are holding last reference to scoped refptr 'socket' here.
   // We can't exit method just like that since 'socket' is going to
   // be destroyed on the UI thread then. Schedule no-op to IO thread
   // so that socket is destroyed on IO instead.
   BrowserThread::PostTask(
       BrowserThread::IO,
       FROM_HERE,
       NewRunnableMethod(
           this,
@@ skipping 144 matching lines @@
     TabStripModel* model = (*it)->tabstrip_model();
     for (int i = 0, size = model->count(); i < size; ++i) {
       NavigationController& controller =
           model->GetTabContentsAt(i)->controller();
       if (controller.session_id().id() == session_id)
         return controller.tab_contents();
     }
   }
   return NULL;
 }