DevTools: refactor remote debugging server to enable content_shell debugging.

content/browser/debugger/devtools_netlog_observer.cc

 // Copyright (c) 2011 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 "content/browser/debugger/devtools_netlog_observer.h"
 
 #include "base/string_tokenizer.h"
 #include "base/string_util.h"
 #include "base/values.h"
 #include "content/public/browser/browser_thread.h"
@@ skipping 222 matching lines @@
     DictionaryValue* dValue = static_cast<DictionaryValue*>(value.get());
     if (!dValue->GetInteger("byte_count", &byte_count))
       return;
 
     encoded_data_length_it->second += byte_count;
   }
 }
 
 void DevToolsNetLogObserver::Attach() {
   DCHECK(!instance_);
-
-  instance_ = new DevToolsNetLogObserver(
-      content::GetContentClient()->browser()->GetNetLog());
+  net::NetLog* net_log = content::GetContentClient()->browser()->GetNetLog();
+  if (net_log)
+    instance_ = new DevToolsNetLogObserver(net_log);
 }
 
 void DevToolsNetLogObserver::Detach() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(instance_);
 
-  delete instance_;
-  instance_ = NULL;
+  if (instance_) {
+    delete instance_;
+    instance_ = NULL;
+  }
 }
 
 DevToolsNetLogObserver* DevToolsNetLogObserver::GetInstance() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 
   return instance_;
 }
 
 // static
 void DevToolsNetLogObserver::PopulateResponseInfo(
@@ skipping 25 matching lines @@
 
   RequestToEncodedDataLengthMap::iterator it =
       dev_tools_net_log_observer->request_to_encoded_data_length_.find(
           source_id);
   if (it == dev_tools_net_log_observer->request_to_encoded_data_length_.end())
     return -1;
   int encoded_data_length = it->second;
   it->second = 0;
   return encoded_data_length;
 }