Removed false dependency from media on the file service interface

mojo/services/media/core/interfaces/seeking_reader.mojom

 // Copyright 2016 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.
 
 [DartPackage="mojo_services"]
 module mojo.media;
 
-import "mojo/services/files/interfaces/types.mojom";
 import "mojo/services/media/common/interfaces/media_common.mojom";
 
 // Reader with seek semantics.
 interface SeekingReader {
   const uint64 kUnknownSize = 0xffffffffffffffff;
 
   // Gets the content size and whether the reader can seek. The |result|
   // callback parameter is |OK| unless there was a problem accessing the
   // content to be read. Other possible values:
   // |NOT_FOUND|     - The content could not be found.
   // |UNKNOWN_ERROR| - Some other error occurred.
   // A |size| value of |kUnknownSize| if the size of the content isn't known.
   Describe() => (MediaResult result, uint64 size, bool can_seek);
 
   // Reads into a data pipe starting at a specified position. If the reader
   // can't seek, position must be 0. The |result| callback parameter is |OK|
   // unless there was a problem performing the read. Other possible values:
   // |NOT_FOUND|        - The content could not be found.
   // |INVALID_ARGUMENT| - The reader can't seek and |position| was non-zero.
   // |UNKNOWN_ERROR|    - Some other error occurred.
   ReadAt(uint64 position) =>
       (MediaResult result, handle<data_pipe_consumer>? data_pipe);
 };