PaymentHandler: PaymentRequestEvent.total should be |object| type.

third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp

Index: third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp
diff --git a/third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp b/third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp
index bdf533512892cf05a55a6e4091717f80b8fd6abc..c4e1e4c5b44ea4162daca63a1a7a28a31dba0d64 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentRequestEvent.cpp
@@ -11,6 +11,7 @@
 #include "modules/serviceworkers/RespondWithObserver.h"
 #include "modules/serviceworkers/ServiceWorkerGlobalScopeClient.h"
 #include "modules/serviceworkers/ServiceWorkerWindowClientCallback.h"
+#include "platform/bindings/ScriptState.h"
 #include "platform/wtf/PtrUtil.h"
 #include "platform/wtf/text/AtomicString.h"
 
@@ -53,8 +54,8 @@ const HeapVector<PaymentMethodData>& PaymentRequestEvent::methodData() const {
   return method_data_;
 }
 
-void PaymentRequestEvent::total(PaymentItem& value) const {
-  value = total_;
+const ScriptValue PaymentRequestEvent::total(ScriptState* script_state) const {
+  return ScriptValue::From(script_state, total_);
 }
 
 const HeapVector<PaymentDetailsModifier>& PaymentRequestEvent::modifiers()