Use the Mac omnibox field's font as the basis for the fonts used in the field and popup.

chrome/browser/autocomplete/autocomplete_popup_view_mac.h

 // Copyright (c) 2009 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 CHROME_BROWSER_AUTOCOMPLETE_AUTOCOMPLETE_POPUP_VIEW_MAC_H_
 #define CHROME_BROWSER_AUTOCOMPLETE_AUTOCOMPLETE_POPUP_VIEW_MAC_H_
 
 #import <Cocoa/Cocoa.h>
 
 #include <string>
@@ skipping 53 matching lines @@
 
   // Returns the popup's model.
   virtual AutocompletePopupModel* GetModel();
 
   // Updates model_'s sense of selected line from the UI before
   // calling edit_view_'s AcceptInput().  Used by internal Objective-C
   // helper object.
   void AcceptInput();
 
   // Return the text to show for the match, based on the match's
-  // contents and description.
-  static NSMutableAttributedString* MatchText(const AutocompleteMatch& match);
+  // contents and description.  Result will be in |font|, with the
+  // boldfaced version used for matches.
+  static NSAttributedString* MatchText(const AutocompleteMatch& match,
+                                       NSFont* font);
 
   // Helper for MatchText() to allow sharing code between the contents
   // and description cases.  Returns NSMutableAttributedString as a
   // convenience for MatchText().
   static NSMutableAttributedString* DecorateMatchedString(
       const std::wstring &matchString,
       const AutocompleteMatch::ACMatchClassifications &classifications,
-      NSColor* textColor);
+      NSColor* textColor, NSFont* font);
 
  private:
   // Create the popup_ instance if needed.
   void CreatePopupIfNeeded();
 
   scoped_ptr<AutocompletePopupModel> model_;
   AutocompleteEditViewMac* edit_view_;
 
   NSTextField* field_;  // owned by tab controller
 
   scoped_nsobject<AutocompleteMatrixTarget> matrix_target_;
   // TODO(shess): Before checkin review implementation to make sure
   // that popup_'s object hierarchy doesn't keep references to
   // destructed objects.
   scoped_nsobject<NSWindow> popup_;
 
   DISALLOW_COPY_AND_ASSIGN(AutocompletePopupViewMac);
 };
 
 #endif  // CHROME_BROWSER_AUTOCOMPLETE_AUTOCOMPLETE_POPUP_VIEW_MAC_H_