Remove DrivePrefetcher and relevant flags.

chrome/browser/chromeos/drive/drive_file_system_interface.h

 // Copyright (c) 2012 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_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_INTERFACE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_INTERFACE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 103 matching lines @@
                             int64 bytes_used)> GetAvailableSpaceCallback;
 
 // Used to get drive filesystem metadata.
 typedef base::Callback<void(const DriveFileSystemMetadata&)>
     GetFilesystemMetadataCallback;
 
 // Priority of a job.  Higher values are lower priority.
 enum ContextType {
   USER_INITIATED,
   BACKGROUND,
-  PREFETCH,
 };
 
 struct DriveClientContext {
   explicit DriveClientContext(ContextType in_type) : type(in_type) {}
   ContextType type;
 };
 
 // Option enum to control eligible entries for searchMetadata().
 // SEARCH_METADATA_ALL is the default to investigate all the entries.
 // SEARCH_METADATA_EXCLUDE_HOSTED_DOCUMENTS excludes the hosted documents.
@@ skipping 330 matching lines @@
   virtual void IterateCache(const CacheIterateCallback& iteration_callback,
                             const base::Closure& completion_callback) = 0;
 
   // Reloads the file system feeds from the server.
   virtual void Reload() = 0;
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_DRIVE_FILE_SYSTEM_INTERFACE_H_