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

base/win/scoped_process_information_unittest.cc

 // Copyright (c) 2012 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 <string>
 
 #include "base/command_line.h"
 #include "base/process/kill.h"
@@ skipping 62 matching lines @@
   process_info.Take();
 }
 
 TEST_F(ScopedProcessInformationTest, TakeProcess) {
   base::win::ScopedProcessInformation process_info;
   MockCreateProcess(&process_info);
 
   HANDLE process = process_info.TakeProcessHandle();
   EXPECT_EQ(kProcessHandle, process);
   EXPECT_EQ(NULL, process_info.process_handle());
-  EXPECT_EQ(0, process_info.process_id());
+  EXPECT_EQ(0u, process_info.process_id());
   EXPECT_TRUE(process_info.IsValid());
   process_info.Take();
 }
 
 TEST_F(ScopedProcessInformationTest, TakeThread) {
   base::win::ScopedProcessInformation process_info;
   MockCreateProcess(&process_info);
 
   HANDLE thread = process_info.TakeThreadHandle();
   EXPECT_EQ(kThreadHandle, thread);
   EXPECT_EQ(NULL, process_info.thread_handle());
-  EXPECT_EQ(0, process_info.thread_id());
+  EXPECT_EQ(0u, process_info.thread_id());
   EXPECT_TRUE(process_info.IsValid());
   process_info.Take();
 }
 
 TEST_F(ScopedProcessInformationTest, TakeBoth) {
   base::win::ScopedProcessInformation process_info;
   MockCreateProcess(&process_info);
 
   process_info.TakeProcessHandle();
   process_info.TakeThreadHandle();
@@ skipping 51 matching lines @@
 
   base::win::ScopedProcessInformation process_info;
   process_info.Set(base_struct);
 
   EXPECT_EQ(kProcessId, process_info.process_id());
   EXPECT_EQ(kThreadId, process_info.thread_id());
   EXPECT_EQ(kProcessHandle, process_info.process_handle());
   EXPECT_EQ(kThreadHandle, process_info.thread_handle());
   base_struct = process_info.Take();
 }