chromeos: Stop calling gdata::GDataCache::GetCacheEntry on UI thread

chrome/browser/chromeos/gdata/gdata_file_system.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_GDATA_GDATA_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILE_SYSTEM_H_
 #pragma once
 
 #include <map>
 #include <string>
@@ skipping 818 matching lines @@
       GDataErrorCode status,
       scoped_ptr<base::Value> created_entry);
 
   // Callback for handling file downloading requests.
   void OnFileDownloaded(
     const GetFileFromCacheParams& params,
     GDataErrorCode status,
     const GURL& content_url,
     const FilePath& downloaded_file_path);
 
+  // Unpins file if cache entry is pinned.
+  void UnpinIfPinned(const FilePath& file_path,
+                     GDataCache::CacheEntry* cache_entry,
+                     bool* cache_entry_is_valid);
+
   // Similar to OnFileDownloaded() but takes |has_enough_space| so we report
   // an error in case we don't have enough disk space.
   void OnFileDownloadedAndSpaceChecked(
       const GetFileFromCacheParams& params,
       GDataErrorCode status,
       const GURL& content_url,
       const FilePath& downloaded_file_path,
       bool* has_enough_space);
 
   // Callback for handling internal StoreToCache() calls after downloading
@@ skipping 633 matching lines @@
 
   ObserverList<Observer> observers_;
 
   // The token is used to post tasks to the blocking pool in sequence.
   const base::SequencedWorkerPool::SequenceToken sequence_token_;
 };
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_FILE_SYSTEM_H_