Mac: Fix PlatformFontMac::DeriveFont.

ui/gfx/font_unittest.cc

Index: ui/gfx/font_unittest.cc
diff --git a/ui/gfx/font_unittest.cc b/ui/gfx/font_unittest.cc
index b93589ddd724af0f43986d5aa55673873c31a028..a5ac50888fb9e3f92f172671f602ac4bca297dc7 100644
--- a/ui/gfx/font_unittest.cc
+++ b/ui/gfx/font_unittest.cc
@@ -158,6 +158,19 @@ TEST_F(FontTest, MAYBE_GetActualFontNameForTesting) {
             base::ToLowerASCII(fallback_font.GetActualFontNameForTesting()));
 }
 
+TEST_F(FontTest, DeriveFont) {
+  Font cf("Arial", 8);
+  const int kSizeDelta = 2;
+  Font cf_underlined =
+      cf.Derive(0, cf.GetStyle() | gfx::Font::UNDERLINE, cf.GetWeight());
+  Font cf_underlined_resized = cf_underlined.Derive(
+      kSizeDelta, cf_underlined.GetStyle(), cf_underlined.GetWeight());
+  EXPECT_EQ(cf.GetStyle() | gfx::Font::UNDERLINE,
+            cf_underlined_resized.GetStyle());
+  EXPECT_EQ(cf.GetFontSize() + kSizeDelta, cf_underlined_resized.GetFontSize());
+  EXPECT_EQ(cf.GetWeight(), cf_underlined_resized.GetWeight());
+}
+
 #if defined(OS_WIN)
 TEST_F(FontTest, DeriveResizesIfSizeTooSmall) {
   Font cf("Arial", 8);