Break up common_custom_types.mojom.

components/font_service/public/interfaces/font_service.mojom

 // Copyright 2014 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.
 
 module font_service.mojom;
 
-import "mojo/common/common_custom_types.mojom";
+import "mojo/common/file.mojom";
 
 enum TypefaceSlant {
   ROMAN = 0,
   ITALIC = 1,
   OBLIQUE = 2,
 };
 
 struct TypefaceStyle {
   uint16 weight;
   uint8 width;
@@ skipping 18 matching lines @@
 // up a service to match fonts and load them,
 interface FontService {
   // Returns the best match for |family_name| and |style|. On error, returns a
   // null |identity|.
   MatchFamilyName(string family_name, TypefaceStyle style) =>
       (FontIdentity? identity, string family_name, TypefaceStyle style);
 
   // Returns a handle to the raw font specified by |id_number|.
   OpenStream(uint32 id_number) => (mojo.common.mojom.File? font_handle);
 };