drive: Stop mentioning about symlinks

chrome/browser/chromeos/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_FILE_SYSTEM_INTERFACE_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_INTERFACE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 426 matching lines @@
   // Note that this method expects that the |cached_file_path| is the path
   // returned by MarkCacheFileAsMounted().
   // |callback| must not be null.
   virtual void MarkCacheFileAsUnmounted(
       const base::FilePath& cache_file_path,
       const FileOperationCallback& callback) = 0;
 
   // Gets the cache entry for file corresponding to |resource_id| and |md5|
   // and runs |callback| with true and the found entry if the entry exists
   // in the cache map. Otherwise, runs |callback| with false.
-  // |md5| can be empty if only matching |resource_id| is desired, which may
-  // happen when looking for pinned entries where symlinks' filenames have no
-  // extension and hence no md5.
+  // |md5| can be empty if only matching |resource_id| is desired.
   // |callback| must not be null.
   virtual void GetCacheEntryByResourceId(
       const std::string& resource_id,
       const std::string& md5,
       const GetCacheEntryCallback& callback) = 0;
 
   // Reloads the file system feeds from the server.
   virtual void Reload() = 0;
 };
 
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_SYSTEM_INTERFACE_H_