Check for method.returns_promise around ExceptionState::throwIfNeeded

third_party/WebKit/Source/bindings/templates/methods.cpp

Index: third_party/WebKit/Source/bindings/templates/methods.cpp
diff --git a/third_party/WebKit/Source/bindings/templates/methods.cpp b/third_party/WebKit/Source/bindings/templates/methods.cpp
index 7da229e550055d6fe6ba1edcd669ed0be57fdff7..6edab4054c04c24514ca8b5d333285094f62b6b4 100644
--- a/third_party/WebKit/Source/bindings/templates/methods.cpp
+++ b/third_party/WebKit/Source/bindings/templates/methods.cpp
@@ -208,7 +208,9 @@ if (!{{argument.name}}{% if argument.is_nullable %} && !isUndefinedOrNull(info[{
 {# Invalid enum values: http://www.w3.org/TR/WebIDL/#idl-enums #}
 {{declare_enum_validation_variable(argument.enum_values)}}
 if (!isValidEnum({{argument.name}}, validValues, WTF_ARRAY_LENGTH(validValues), "{{argument.enum_type}}", exceptionState)) {
+    {% if not method.returns_promise %}
     exceptionState.throwIfNeeded();
+    {% endif %}
     return;
 }
 {% elif argument.idl_type == 'Promise' %}