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

base/win/scoped_process_information_unittest.cc

Index: base/win/scoped_process_information_unittest.cc
diff --git a/base/win/scoped_process_information_unittest.cc b/base/win/scoped_process_information_unittest.cc
index 614504d414efa87b33bad5d78c17f715cbbe12da..799b273f0ed58dfda622581b69d6931400a93cfd 100644
--- a/base/win/scoped_process_information_unittest.cc
+++ b/base/win/scoped_process_information_unittest.cc
@@ -80,7 +80,7 @@ TEST_F(ScopedProcessInformationTest, TakeProcess) {
   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();
 }
@@ -92,7 +92,7 @@ TEST_F(ScopedProcessInformationTest, TakeThread) {
   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();
 }