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

content/common/font_descriptor_mac.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CONTENT_COMMON_FONT_DESCRIPTOR_MAC_H_
 #define CONTENT_COMMON_FONT_DESCRIPTOR_MAC_H_
 #pragma once
 
 #include "base/string16.h"
 
 #ifdef __OBJC__
 @class NSFont;
 #else
 class NSFont;
 #endif
 
 // Container to allow serializing an NSFont over IPC.
 struct FontDescriptor {
   explicit FontDescriptor(NSFont* font);
+  FontDescriptor(string16 name, float size);
 
   FontDescriptor() : font_point_size(0) {}
 
   // Return an autoreleased NSFont corresponding to the font description.
-  NSFont* nsFont() const;
+  NSFont* ToNSFont() const;
 
   // Name of the font.
   string16 font_name;
 
   // Size in points.
   float font_point_size;
 };
 
 #endif  // CONTENT_COMMON_FONT_DESCRIPTOR_MAC_H_