bindings: Use ExceptionMessages when an interface/callback conversion fails.

third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl b/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
index 289ea7ebb4aca137de40131adcd5010ace36367c..bbd979c5b9b12cab33e22c750d0d187d01e2f380 100644
--- a/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
+++ b/third_party/WebKit/Source/bindings/templates/interface.cpp.tmpl
@@ -893,8 +893,10 @@ v8::Local<v8::Object> {{v8_class}}::findInstanceInPrototypeChain(v8::Local<v8::V
 {% block native_value_traits %}
 {{cpp_class}}* NativeValueTraits<{{cpp_class}}>::NativeValue(v8::Isolate* isolate, v8::Local<v8::Value> value, ExceptionState& exceptionState) {
   {{cpp_class}}* nativeValue = {{v8_class}}::toImplWithTypeCheck(isolate, value);
-  if (!nativeValue)
-    exceptionState.ThrowTypeError("Unable to convert value to {{interface_name}}.");
+  if (!nativeValue) {
+    exceptionState.ThrowTypeError(ExceptionMessages::FailedToConvertJSValue(
+        "{{interface_name}}"));
+  }
   return nativeValue;
 }