[Mac] Implement the system dictionary popup by implementing NSTextInput methods.

content/common/font_descriptor_mac.mm

Index: content/common/font_descriptor_mac.mm
diff --git a/content/common/font_descriptor_mac.mm b/content/common/font_descriptor_mac.mm
index 90c7986c311853b215f86343a93a60c5793d3c77..c8e3112be091e61c3032f18b837b36b64866d830 100644
--- a/content/common/font_descriptor_mac.mm
+++ b/content/common/font_descriptor_mac.mm
@@ -13,7 +13,12 @@ FontDescriptor::FontDescriptor(NSFont* font) {
   font_point_size = [font pointSize];
 }
 
-NSFont* FontDescriptor::nsFont() const {
+FontDescriptor::FontDescriptor(string16 name, float size) {
+  font_name = name;
+  font_point_size = size;
+}
+
+NSFont* FontDescriptor::ToNSFont() const {
   NSString* font_name_ns = base::SysUTF16ToNSString(font_name);
   NSFont* font = [NSFont fontWithName:font_name_ns size:font_point_size];
   return font;