V8 Binding: Introduce toNativeWithTypeCheck

Source/bindings/v8/custom/V8DocumentCustom.cpp

Index: Source/bindings/v8/custom/V8DocumentCustom.cpp
diff --git a/Source/bindings/v8/custom/V8DocumentCustom.cpp b/Source/bindings/v8/custom/V8DocumentCustom.cpp
index f59fcc685b27c2a93e10178d14c8b0dbda78930c..b1913f847e8e5327a32d4433a36cb1bf88e1cd72 100644
--- a/Source/bindings/v8/custom/V8DocumentCustom.cpp
+++ b/Source/bindings/v8/custom/V8DocumentCustom.cpp
@@ -63,9 +63,7 @@ void V8Document::evaluateMethodCustom(const v8::FunctionCallbackInfo<v8::Value>&
     RefPtr<Document> document = V8Document::toNative(info.Holder());
     ExceptionState exceptionState(ExceptionState::ExecutionContext, "evaluate", "Document", info.Holder(), info.GetIsolate());
     V8TRYCATCH_FOR_V8STRINGRESOURCE_VOID(V8StringResource<>, expression, info[0]);
-    RefPtr<Node> contextNode;
-    if (V8Node::hasInstance(info[1], info.GetIsolate()))
-        contextNode = V8Node::toNative(v8::Handle<v8::Object>::Cast(info[1]));
+    RefPtr<Node> contextNode = V8Node::toNativeWithTypeCheck(info.GetIsolate(), info[1]);
 
     const int resolverArgumentIndex = 2;
     RefPtrWillBeRawPtr<XPathNSResolver> resolver = toXPathNSResolver(info[resolverArgumentIndex], info.GetIsolate());
@@ -76,10 +74,7 @@ void V8Document::evaluateMethodCustom(const v8::FunctionCallbackInfo<v8::Value>&
     }
 
     int type = toInt32(info[3]);
-    RefPtrWillBeRawPtr<XPathResult> inResult;
-    if (V8XPathResult::hasInstance(info[4], info.GetIsolate()))
-        inResult = V8XPathResult::toNative(v8::Handle<v8::Object>::Cast(info[4]));
-
+    RefPtrWillBeRawPtr<XPathResult> inResult = V8XPathResult::toNativeWithTypeCheck(info.GetIsolate(), info[4]);
     V8TRYCATCH_VOID(RefPtrWillBeRawPtr<XPathResult>, result, DocumentXPathEvaluator::evaluate(document.get(), expression, contextNode.get(), resolver.release(), type, inResult.get(), exceptionState));
     if (exceptionState.throwIfNeeded())
         return;