gdata: Make WeakPtrFactory the last parameter

chrome/browser/chromeos/gdata/gdata_cache.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_CACHE_H_
 #define CHROME_BROWSER_CHROMEOS_GDATA_GDATA_CACHE_H_
 
 #include <map>
 #include <string>
 #include <vector>
@@ skipping 412 matching lines @@
   // The root directory of the cache (i.e. <user_profile_dir>/GCache/v1).
   const FilePath cache_root_path_;
   // Paths for all subdirectories of GCache, one for each
   // GDataCache::CacheSubDirectoryType enum.
   const std::vector<FilePath> cache_paths_;
   scoped_refptr<base::SequencedTaskRunner> blocking_task_runner_;
 
   // The cache state data. This member must be access only on the blocking pool.
   scoped_ptr<GDataCacheMetadata> metadata_;
 
-  // WeakPtrFactory and WeakPtr bound to the UI thread.
-  base::WeakPtrFactory<GDataCache> ui_weak_ptr_factory_;
-  base::WeakPtr<GDataCache> ui_weak_ptr_;
-
   // List of observers, this member must be accessed on UI thread.
   ObserverList<Observer> observers_;
 
+  // Note: This should remain the last member so it'll be destroyed and
+  // invalidate its weak pointers before any other members are destroyed.
+  base::WeakPtrFactory<GDataCache> weak_ptr_factory_;
   DISALLOW_COPY_AND_ASSIGN(GDataCache);
 };
 
 
 // The minimum free space to keep. GDataFileSystem::GetFileByPath() returns
 // GDATA_FILE_ERROR_NO_SPACE if the available space is smaller than
 // this value.
 //
 // Copied from cryptohome/homedirs.h.
 // TODO(satorux): Share the constant.
 const int64 kMinFreeSpace = 512 * 1LL << 20;
 
 // Interface class used for getting the free disk space. Only for testing.
 class FreeDiskSpaceGetterInterface {
  public:
   virtual ~FreeDiskSpaceGetterInterface() {}
   virtual int64 AmountOfFreeDiskSpace() const = 0;
 };
 
 // Sets the free disk space getter for testing.
 // The existing getter is deleted.
 void SetFreeDiskSpaceGetterForTesting(
     FreeDiskSpaceGetterInterface* getter);
 
 }  // namespace gdata
 
 #endif  // CHROME_BROWSER_CHROMEOS_GDATA_GDATA_CACHE_H_