clang/win: Let remaining chromium_code targets build with -Wextra.

chrome/installer/util/wmi_unittest.cc

 // Copyright (c) 2006-2008 The Chromium 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 <windows.h>
 
 #include "chrome/installer/util/wmi.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
 namespace installer {
 
 TEST(WMITest, TestLocalConnectionSecurityBlanket) {
   IWbemServices* services = NULL;
   EXPECT_TRUE(WMI::CreateLocalConnection(true, &services));
   ASSERT_TRUE(NULL != services);
   ULONG refs = services->Release();
-  EXPECT_EQ(refs, 0);
+  EXPECT_EQ(0u, refs);
 }
 
 TEST(WMITest, TestLocalConnectionNoSecurityBlanket) {
   IWbemServices* services = NULL;
   EXPECT_TRUE(WMI::CreateLocalConnection(false, &services));
   ASSERT_TRUE(NULL != services);
   ULONG refs = services->Release();
-  EXPECT_EQ(refs, 0);
+  EXPECT_EQ(0u, refs);
 }
 
 TEST(WMITest, TestCreateClassMethod) {
   IWbemServices* wmi_services = NULL;
   EXPECT_TRUE(WMI::CreateLocalConnection(true, &wmi_services));
   ASSERT_TRUE(NULL != wmi_services);
   IWbemClassObject* class_method = NULL;
   EXPECT_TRUE(WMI::CreateClassMethodObject(wmi_services,
                                                L"Win32_ShortcutFile",
                                                L"Rename", &class_method));
   ASSERT_TRUE(NULL != class_method);
   ULONG refs = class_method->Release();
-  EXPECT_EQ(refs, 0);
+  EXPECT_EQ(0u, refs);
   refs = wmi_services->Release();
-  EXPECT_EQ(refs, 0);
+  EXPECT_EQ(0u, refs);
 }
 
 // Creates an instance of cmd which executes 'echo' and exits immediately.
 TEST(WMITest, TestLaunchProcess) {
   int pid = 0;
   bool result = WMIProcess::Launch(L"cmd.exe /c echo excelent!", &pid);
   EXPECT_TRUE(result);
   EXPECT_GT(pid, 0);
 }
 
 }  // namespace installer