Mac: Fix PlatformFontMac::DeriveFont for underline font style.

ui/gfx/platform_font_mac.mm

Index: ui/gfx/platform_font_mac.mm
diff --git a/ui/gfx/platform_font_mac.mm b/ui/gfx/platform_font_mac.mm
index 1df9e6922196b6df791b3a67db9e676490783a2e..2e08a033aaf1c0d56f2ecffce10b9f5bc926c9af 100644
--- a/ui/gfx/platform_font_mac.mm
+++ b/ui/gfx/platform_font_mac.mm
@@ -63,7 +63,7 @@
     : PlatformFontMac([NSFont systemFontOfSize:[NSFont systemFontSize]]) {
 }
 
-PlatformFontMac::PlatformFontMac(NativeFont native_font)
+PlatformFontMac::PlatformFontMac(NativeFont native_font, bool underline)
     : native_font_([native_font retain]),
       font_name_(base::SysNSStringToUTF8([native_font_ familyName])),
       font_size_([native_font_ pointSize]),
@@ -72,6 +72,8 @@
   NSFontSymbolicTraits traits = [[native_font fontDescriptor] symbolicTraits];
   if (traits & NSFontItalicTrait)
     font_style_ |= Font::ITALIC;
+  if (underline)
+    font_style_ |= Font::UNDERLINE;
   if (traits & NSFontBoldTrait)
     font_weight_ = Font::Weight::BOLD;
 
@@ -79,16 +81,10 @@
 }
 
 PlatformFontMac::PlatformFontMac(const std::string& font_name, int font_size)
-    : native_font_([NSFontWithSpec(font_name,
-                                   font_size,
-                                   Font::NORMAL,
-                                   Font::Weight::NORMAL) retain]),
-      font_name_(font_name),
-      font_size_(font_size),
-      font_style_(Font::NORMAL),
-      font_weight_(Font::Weight::NORMAL) {
-  CalculateMetricsAndInitRenderParams();
-}
+    : PlatformFontMac(font_name,

[karandeepb, 2016/08/05 11:03:07]

Just a small cleanup.

[Avi (use Gerrit), 2016/08/05 14:54:59]

Acknowledged.

+                      font_size,
+                      Font::NORMAL,
+                      Font::Weight::NORMAL) {}
 
 ////////////////////////////////////////////////////////////////////////////////
 // PlatformFontMac, PlatformFont implementation:
@@ -98,10 +94,12 @@
                                  Font::Weight weight) const {
   if (native_font_ && style == font_style_ && weight == font_weight_) {
     // System fonts have special attributes starting with 10.11. They should be
-    // requested using the same descriptor to preserve these attributes.
-    return Font(new PlatformFontMac([NSFont
-        fontWithDescriptor:[native_font_ fontDescriptor]
-                      size:font_size_ + size_delta]));
+    // requested using the same descriptor to preserve these attributes. Since
+    // NSFont does not support underline as a descriptor, pass it explicitly.
+    return Font(new PlatformFontMac(
+        [NSFont fontWithDescriptor:[native_font_ fontDescriptor]
+                              size:font_size_ + size_delta],
+        style & Font::UNDERLINE));
   }
 
   return Font(