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

printing/printing_context_win_unittest.cc

Index: printing/printing_context_win_unittest.cc
diff --git a/printing/printing_context_win_unittest.cc b/printing/printing_context_win_unittest.cc
index 6b2b20f7bd09b8a6e57985896d492e07ea5f46a6..171d97ce75759914ed3c58f76cf799ad73edb83c 100644
--- a/printing/printing_context_win_unittest.cc
+++ b/printing/printing_context_win_unittest.cc
@@ -152,7 +152,7 @@ TEST_F(PrintingContextTest, PrintAll) {
                  base::Unretained(this)));
   EXPECT_EQ(PrintingContext::OK, result());
   PrintSettings settings = context.settings();
-  EXPECT_EQ(settings.ranges().size(), 0);
+  EXPECT_EQ(0u, settings.ranges().size());
 }
 
 TEST_F(PrintingContextTest, Base) {