[DevTools] migrate InspectorDOMAgent to new style

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

Index: third_party/WebKit/Source/modules/accessibility/InspectorAccessibilityAgent.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/InspectorAccessibilityAgent.cpp b/third_party/WebKit/Source/modules/accessibility/InspectorAccessibilityAgent.cpp
index 6b7ddcc722fb34ac001493c2a70b9aea0fc7bda3..0e5d71f0738b04a9bdf5c30dfaf17b824a125cc6 100644
--- a/third_party/WebKit/Source/modules/accessibility/InspectorAccessibilityAgent.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/InspectorAccessibilityAgent.cpp
@@ -389,9 +389,12 @@ void InspectorAccessibilityAgent::getAXNodeChain(
     *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();