Use unique_ptr in CFXA_FM expressions

xfa/fxfa/fm2js/xfa_simpleexpression_unittest.cpp

 // Copyright 2016 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "xfa/fxfa/fm2js/xfa_simpleexpression.h"
 
 #include <memory>
 #include <utility>
 
 #include "testing/gtest/include/gtest/gtest.h"
 #include "third_party/base/ptr_util.h"
 #include "xfa/fxfa/fm2js/xfa_lexer.h"
 
 TEST(FMCallExpression, more_than_32_arguments) {
   // Use sign as it has 3 object parameters at positions 0, 5, and 6.
   auto exp = pdfium::MakeUnique<CXFA_FMIdentifierExpression>(0, L"sign");
 
   std::vector<std::unique_ptr<CXFA_FMSimpleExpression>> args;
   for (size_t i = 0; i < 50; i++)
     args.push_back(pdfium::MakeUnique<CXFA_FMSimpleExpression>(0, TOKnan));
 
-  CXFA_FMCallExpression callExp(0, exp.release(), std::move(args), true);
+  CXFA_FMCallExpression callExp(0, std::move(exp), std::move(args), true);
   CFX_WideTextBuf js;
   callExp.ToJavaScript(js);
 
   // Generate the result javascript string.
   CFX_WideString result = L"sign(";
   for (size_t i = 0; i < 50; i++) {
     if (i > 0)
       result += L", ";
 
     result += L"foxit_xfa_formcalc_runtime.get_fm_";
     // Object positions for sign() method.
     if (i == 0 || i == 5 || i == 6)
       result += L"jsobj()";
     else
       result += L"value()";
   }
   result += L")";
 
   EXPECT_EQ(result.AsStringC(), js.AsStringC());
 }