[DevTools] migrate InspectorDOMAgent to new style

third_party/WebKit/Source/modules/accessibility/InspectorAccessibilityAgent.cpp

 // 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 "modules/accessibility/InspectorAccessibilityAgent.h"
 
 #include "core/HTMLNames.h"
 #include "core/dom/AXObjectCache.h"
 #include "core/dom/DOMNodeIds.h"
 #include "core/dom/Element.h"
@@ skipping 371 matching lines @@
 
 void InspectorAccessibilityAgent::getAXNodeChain(
     ErrorString* errorString,
     int domNodeId,
     bool fetchAncestors,
     std::unique_ptr<protocol::Array<protocol::Accessibility::AXNode>>* nodes) {
   if (!m_domAgent->enabled()) {
     *errorString = "DOM agent must be enabled";
     return;
   }
-  Node* domNode = m_domAgent->assertNode(errorString, domNodeId);
-  if (!domNode)
+  Node* domNode = nullptr;
+  Response response = m_domAgent->assertNode(domNodeId, domNode);
+  if (!response.isSuccess()) {
+    *errorString = response.errorMessage();
     return;
+  }
 
   Document& document = domNode->document();
   document.updateStyleAndLayoutIgnorePendingStylesheets();
   DocumentLifecycle::DisallowTransitionScope disallowTransition(
       document.lifecycle());
   LocalFrame* localFrame = document.frame();
   if (!localFrame) {
     *errorString = "Frame is detached.";
     return;
   }
@@ skipping 119 matching lines @@
   }
 }
 
 DEFINE_TRACE(InspectorAccessibilityAgent) {
   visitor->trace(m_page);
   visitor->trace(m_domAgent);
   InspectorBaseAgent::trace(visitor);
 }
 
 }  // namespace blink