Use v8AtomicString instead of v8::String::NewFromUtf8

Source/bindings/templates/attributes.cpp

 {##############################################################################}
 {% macro attribute_getter(attribute, world_suffix) %}
 {% filter conditional(attribute.conditional_string) %}
 static void {{attribute.name}}AttributeGetter{{world_suffix}}(
 {%- if attribute.is_expose_js_accessors %}
 const v8::FunctionCallbackInfo<v8::Value>& info
 {%- else %}
 const v8::PropertyCallbackInfo<v8::Value>& info
 {%- endif %})
 {
     {% if attribute.is_unforgeable %}
     v8::Handle<v8::Object> holder = info.This()->FindInstanceInPrototypeChain({{v8_class}}::domTemplate(info.GetIsolate(), worldType(info.GetIsolate())));
     if (holder.IsEmpty())
         return;
     {{cpp_class}}* imp = {{v8_class}}::toNative(holder);
     {% endif %}
     {% if attribute.cached_attribute_validation_method %}
-    v8::Handle<v8::String> propertyName = v8::String::NewFromUtf8(info.GetIsolate(), "{{attribute.name}}", v8::String::kInternalizedString);
+    v8::Handle<v8::String> propertyName = v8AtomicString(info.GetIsolate(), "{{attribute.name}}");
     {{cpp_class}}* imp = {{v8_class}}::toNative(info.Holder());
     if (!imp->{{attribute.cached_attribute_validation_method}}()) {
         v8::Handle<v8::Value> jsValue = info.Holder()->GetHiddenValue(propertyName);
         if (!jsValue.IsEmpty()) {
             v8SetReturnValue(info, jsValue);
             return;
         }
     }
     {% elif not (attribute.is_static or attribute.is_unforgeable) %}
     {{cpp_class}}* imp = {{v8_class}}::toNative(info.Holder());
@@ skipping 130 matching lines @@
     CustomElementCallbackDispatcher::CallbackDeliveryScope deliveryScope;
     {% endif %}
     {% if attribute.is_call_with_execution_context %}
     ExecutionContext* scriptContext = getExecutionContext();
     {% endif %}
     {{attribute.cpp_setter}};
     {% if attribute.is_setter_raises_exception %}
     exceptionState.throwIfNeeded();
     {% endif %}
     {% if attribute.cached_attribute_validation_method %}
-    info.Holder()->DeleteHiddenValue(v8::String::NewFromUtf8(info.GetIsolate(), "{{attribute.name}}", v8::String::kInternalizedString)); // Invalidate the cached value.
+    info.Holder()->DeleteHiddenValue(v8AtomicString(info.GetIsolate(), "{{attribute.name}}")); // Invalidate the cached value.
     {% endif %}
 }
 {% endfilter %}
 {% endmacro %}
 
 
 {##############################################################################}
 {% macro attribute_setter_callback(attribute, world_suffix) %}
 {% filter conditional(attribute.conditional_string) %}
 static void {{attribute.name}}AttributeSetterCallback{{world_suffix}}(
@@ skipping 25 matching lines @@
     {% endif %}
     {% if attribute.has_custom_setter %}
     {{v8_class}}::{{attribute.name}}AttributeSetterCustom(jsValue, info);
     {% else %}
     {{cpp_class}}V8Internal::{{attribute.name}}AttributeSetter{{world_suffix}}(jsValue, info);
     {% endif %}
     TRACE_EVENT_SET_SAMPLING_STATE("V8", "Execution");
 }
 {% endfilter %}
 {% endmacro %}