drive: Stop mentioning about symlinks

chrome/browser/chromeos/drive/file_cache_metadata.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_CACHE_METADATA_H_
 #define CHROME_BROWSER_CHROMEOS_DRIVE_FILE_CACHE_METADATA_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 48 matching lines @@
   // Adds a new cache entry corresponding to |resource_id| if it doesn't
   // exist, otherwise update the existing entry.
   virtual void AddOrUpdateCacheEntry(const std::string& resource_id,
                                      const FileCacheEntry& cache_entry) = 0;
 
   // Removes entry corresponding to |resource_id| from cache map.
   virtual void RemoveCacheEntry(const std::string& resource_id) = 0;
 
   // Gets the cache entry for file corresponding to |resource_id| and |md5|
   // and returns true if entry exists in cache map.  Otherwise, returns 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.
   virtual bool GetCacheEntry(const std::string& resource_id,
                              const std::string& md5,
                              FileCacheEntry* entry) = 0;
 
   // Removes temporary files (files in CACHE_TYPE_TMP) from the cache map.
   virtual void RemoveTemporaryFiles() = 0;
 
   // Iterates over all the cache entries synchronously. |callback| is called
   // on each cache entry.
   virtual void Iterate(const CacheIterateCallback& callback) = 0;
 
  protected:
   explicit FileCacheMetadata(base::SequencedTaskRunner* blocking_task_runner);
 
   // Checks whether the current thread is on the right sequenced worker pool
   // with the right sequence ID. If not, DCHECK will fail.
   void AssertOnSequencedWorkerPool();
 
  private:
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(FileCacheMetadata);
 };
 
 }  // namespace internal
 }  // namespace drive
 
 #endif  // CHROME_BROWSER_CHROMEOS_DRIVE_FILE_CACHE_METADATA_H_