bindings: Throw a type error if converting an interface or callback function fails.

third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCustomConstructor.cpp

Index: third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCustomConstructor.cpp
diff --git a/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCustomConstructor.cpp b/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCustomConstructor.cpp
index 0143066c4594bd3b1a8dfc0e558291eca173926a..cabe2b47ed60574143fed99e6d02c54e82e983ed 100644
--- a/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCustomConstructor.cpp
+++ b/third_party/WebKit/Source/bindings/tests/results/core/V8TestInterfaceCustomConstructor.cpp
@@ -101,7 +101,10 @@ TestInterfaceCustomConstructor* V8TestInterfaceCustomConstructor::toImplWithType
 }
 
 TestInterfaceCustomConstructor* NativeValueTraits<TestInterfaceCustomConstructor>::nativeValue(v8::Isolate* isolate, v8::Local<v8::Value> value, ExceptionState& exceptionState) {
-  return V8TestInterfaceCustomConstructor::toImplWithTypeCheck(isolate, value);
+  TestInterfaceCustomConstructor* nativeValue = V8TestInterfaceCustomConstructor::toImplWithTypeCheck(isolate, value);
+  if (!nativeValue)
+    exceptionState.throwTypeError("Unable to convert value to TestInterfaceCustomConstructor.");
+  return nativeValue;
 }
 
 }  // namespace blink