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

ui/gfx/icon_util_unittest.cc

Index: ui/gfx/icon_util_unittest.cc
diff --git a/ui/gfx/icon_util_unittest.cc b/ui/gfx/icon_util_unittest.cc
index f47d190b2ba5ff47338393a36032c7da3a31c89a..d72c2cc9651279121195d70b1d8670eb7f628f80 100644
--- a/ui/gfx/icon_util_unittest.cc
+++ b/ui/gfx/icon_util_unittest.cc
@@ -417,7 +417,7 @@ TEST_F(IconUtilTest, TestCreateImageFamilyFromIconResource) {
     images.push_back(image);
 
   // Assert that the family contains all of the images from the icon resource.
-  EXPECT_EQ(5, images.size());
+  EXPECT_EQ(5u, images.size());
   EXPECT_EQ(16, images[0].Width());
   EXPECT_EQ(24, images[1].Width());
   EXPECT_EQ(32, images[2].Width());