Code change to avoid signed/unsigned mismatch warnings

core/fxcrt/fx_basic_gcc_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 "core/fxcrt/include/fx_system.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 TEST(fxcrt, FXSYS_atoi) {
   EXPECT_EQ(0, FXSYS_atoi(""));
   EXPECT_EQ(0, FXSYS_atoi("0"));
@@ skipping 75 matching lines @@
 
   // Out of range values.
   EXPECT_EQ(9223372036854775807LL,
             FXSYS_wtoi64(L"922337203685471234123475807"));
   EXPECT_EQ(9223372036854775807LL, FXSYS_wtoi64(L"9223372036854775808"));
   EXPECT_EQ(-9223372036854775807LL - 1LL,
             FXSYS_wtoi64(L"-9223372036854775810"));
 }
 
 TEST(fxcrt, FXSYS_atoui) {
-  EXPECT_EQ(0, FXSYS_atoui(""));
-  EXPECT_EQ(0, FXSYS_atoui("0"));
+  EXPECT_EQ(0u, FXSYS_atoui(""));
+  EXPECT_EQ(0u, FXSYS_atoui("0"));
   EXPECT_EQ(4294967295, FXSYS_atoui("-1"));
-  EXPECT_EQ(2345, FXSYS_atoui("2345"));
+  EXPECT_EQ(2345u, FXSYS_atoui("2345"));
   // Handle the sign.
   EXPECT_EQ(4294964951, FXSYS_atoui("-2345"));
-  EXPECT_EQ(2345, FXSYS_atoui("+2345"));
+  EXPECT_EQ(2345u, FXSYS_atoui("+2345"));
   // The max value.
   EXPECT_EQ(4294967295, FXSYS_atoui("4294967295"));
-  EXPECT_EQ(9, FXSYS_atoui("9x9"));
+  EXPECT_EQ(9u, FXSYS_atoui("9x9"));
 
   // Out of range values.
   EXPECT_EQ(4294967295, FXSYS_atoui("2147483623423412348"));
   EXPECT_EQ(4294967295, FXSYS_atoui("4294967296"));
   EXPECT_EQ(4294967295, FXSYS_atoui("-4294967345"));
 }