WTF/std normalization: replace WTF::Vector::last with ::back

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

Index: third_party/WebKit/Source/modules/payments/PaymentTestHelper.cpp
diff --git a/third_party/WebKit/Source/modules/payments/PaymentTestHelper.cpp b/third_party/WebKit/Source/modules/payments/PaymentTestHelper.cpp
index c42805d6137384da5293b6cf0f9d1fc369df4f97..e9d25f51cc14e5113de6a172f69255e19d28a5e1 100644
--- a/third_party/WebKit/Source/modules/payments/PaymentTestHelper.cpp
+++ b/third_party/WebKit/Source/modules/payments/PaymentTestHelper.cpp
@@ -189,20 +189,20 @@ PaymentRequestMockFunctionScope::~PaymentRequestMockFunctionScope() {
 v8::Local<v8::Function> PaymentRequestMockFunctionScope::expectCall(
     String* captor) {
   m_mockFunctions.append(new MockFunction(m_scriptState, captor));
-  EXPECT_CALL(*m_mockFunctions.last(), call(testing::_));
-  return m_mockFunctions.last()->bind();
+  EXPECT_CALL(*m_mockFunctions.back(), call(testing::_));
+  return m_mockFunctions.back()->bind();
 }
 
 v8::Local<v8::Function> PaymentRequestMockFunctionScope::expectCall() {
   m_mockFunctions.append(new MockFunction(m_scriptState));
-  EXPECT_CALL(*m_mockFunctions.last(), call(testing::_));
-  return m_mockFunctions.last()->bind();
+  EXPECT_CALL(*m_mockFunctions.back(), call(testing::_));
+  return m_mockFunctions.back()->bind();
 }
 
 v8::Local<v8::Function> PaymentRequestMockFunctionScope::expectNoCall() {
   m_mockFunctions.append(new MockFunction(m_scriptState));
-  EXPECT_CALL(*m_mockFunctions.last(), call(testing::_)).Times(0);
-  return m_mockFunctions.last()->bind();
+  EXPECT_CALL(*m_mockFunctions.back(), call(testing::_)).Times(0);
+  return m_mockFunctions.back()->bind();
 }
 
 ACTION_P(SaveValueIn, captor) {