DevTools: Fix access violation (null pointer) on document tear down.

webkit/glue/webdevtoolsagent_impl.cc

 // Copyright (c) 2009 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 "config.h"
 
 #include <string>
 
 #include "Document.h"
 #include "EventListener.h"
@@ skipping 60 matching lines @@
                             this));
   dom_agent_impl_.set(new DomAgentImpl(dom_agent_delegate_stub_.get()));
 
   // We are potentially attaching to the running page -> init agents with
   // Document if any.
   Page* page = web_view_impl_->page();
   Document* doc = page->mainFrame()->document();
   if (doc) {
     // Reuse existing context in case detached/attached.
     if (utility_context_.IsEmpty()) {
-      debugger_agent_impl_->CreateUtilityContext(doc, &utility_context_);
+      debugger_agent_impl_->ResetUtilityContext(doc, &utility_context_);
     }
     dom_agent_impl_->SetDocument(doc);
     net_agent_impl_->SetDocument(doc);
   }
 
   // Populate console.
   for (Vector<ConsoleMessage>::iterator it = console_log_.begin();
        it != console_log_.end(); ++it) {
     DictionaryValue message;
     Serialize(*it, &message);
@@ skipping 17 matching lines @@
   }
 
   // We were attached prior to the page load -> init agents with Document.
   Document* doc;
   if (ready) {
     Page* page = web_view_impl_->page();
     doc = page->mainFrame()->document();
   } else {
     doc = NULL;
   }
-  debugger_agent_impl_->CreateUtilityContext(doc, &utility_context_);
+  debugger_agent_impl_->ResetUtilityContext(doc, &utility_context_);
   dom_agent_impl_->SetDocument(doc);
   net_agent_impl_->SetDocument(doc);
 }
 
 void WebDevToolsAgentImpl::DidCommitLoadForFrame(
     WebViewImpl* webview,
     WebFrame* frame,
     bool is_new_navigation) {
   if (webview->GetMainFrame() == frame) {
     net_agent_impl_->DidCommitMainResourceLoad();
@@ skipping 141 matching lines @@
     const std::string& command,
     int caller_id) {
   DebuggerAgentManager::ExecuteDebuggerCommand(command, caller_id);
 }
 
 // static
 void WebDevToolsAgent::SetMessageLoopDispatchHandler(
     MessageLoopDispatchHandler handler) {
   DebuggerAgentManager::SetMessageLoopDispatchHandler(handler);
 }