No need to stop the one shot timer once the timer fired.

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

Index: third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
diff --git a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
index be948757a6651bef88a1858acc88fbbd932a4c02..d034871f6dafea2a63b09b631a8973ed66d5d4d1 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentRequest.cpp
@@ -25,6 +25,7 @@
 #include "mojo/public/cpp/bindings/wtf_array.h"
 #include "platform/mojo/MojoHelper.h"
 #include "public/platform/InterfaceProvider.h"
+#include "public/platform/WebTraceLocation.h"

[please use gerrit instead, 2016/08/08 16:35:58]

Why was this include added?

[pals, 2016/08/09 01:53:09]

Its for the BLINK_FROM_HERE.

 #include "wtf/HashSet.h"
 #include <utility>
 
@@ -488,6 +489,7 @@ DEFINE_TRACE(PaymentRequest)
 
 void PaymentRequest::onCompleteTimeoutForTesting()
 {
+    m_completeTimer.stop();
     onCompleteTimeout(0);
 }
 
@@ -686,7 +688,6 @@ void PaymentRequest::OnAbort(bool abortedSuccessfully)
 
 void PaymentRequest::onCompleteTimeout(TimerBase*)
 {
-    m_completeTimer.stop();
     m_paymentProvider->Complete(mojom::blink::PaymentComplete(Fail));
     clearResolversAndCloseMojoConnection();
 }