Remove dead code in media galleries file system registry.

chrome/browser/media_galleries/media_file_system_registry.cc

 // 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.
 
 #include "chrome/browser/media_galleries/media_file_system_registry.h"
 
 #include <set>
 #include <vector>
 
 #include "base/bind.h"
@@ skipping 267 matching lines @@
     for (std::set<MediaGalleryPrefId>::const_iterator id = galleries.begin();
          id != galleries.end();
          ++id) {
       device_ids->insert(galleries_info.find(*id)->second.device_id);
     }
     MediaStorageUtil::FilterAttachedDevices(device_ids, base::Bind(
         &ExtensionGalleriesHost::GetMediaFileSystemsForAttachedDevices, this,
         base::Owned(device_ids), galleries, galleries_info, callback));
   }
 
-  void RevokeOldGalleries(const MediaGalleryPrefIdSet& new_galleries) {
-    if (new_galleries.size() == pref_id_map_.size())
-      return;
-
-    MediaGalleryPrefIdSet old_galleries;
-    for (PrefIdFsInfoMap::const_iterator it = pref_id_map_.begin();
-         it != pref_id_map_.end();
-         ++it) {
-      old_galleries.insert(it->first);
-    }
-    MediaGalleryPrefIdSet invalid_galleries =
-        base::STLSetDifference<MediaGalleryPrefIdSet>(old_galleries,
-                                                      new_galleries);
-    for (MediaGalleryPrefIdSet::const_iterator it = invalid_galleries.begin();
-         it != invalid_galleries.end();
-         ++it) {
-      RevokeGalleryByPrefId(*it);
-    }
-  }
-
   // Revoke the file system for |id| if this extension has created one for |id|.
   void RevokeGalleryByPrefId(MediaGalleryPrefId id) {
     PrefIdFsInfoMap::iterator gallery = pref_id_map_.find(id);
     if (gallery == pref_id_map_.end())
       return;
 
     file_system_context_->RevokeFileSystem(gallery->second.fsid);
     pref_id_map_.erase(gallery);
 
     if (pref_id_map_.empty()) {
@@ skipping 27 matching lines @@
     std::vector<MediaFileSystemInfo> result;
 
     if (rph_refs_.empty()) {
       // We're actually in the middle of shutdown, and Filter...() lagging
       // which can invoke this method interleaved in the destruction callback
       // sequence and re-populate pref_id_map_.
       callback.Run(result);
       return;
     }
 
-    MediaGalleryPrefIdSet new_galleries;
     for (std::set<MediaGalleryPrefId>::const_iterator pref_id_it =
              galleries.begin();
          pref_id_it != galleries.end();
          ++pref_id_it) {
       const MediaGalleryPrefId& pref_id = *pref_id_it;
       const MediaGalleryPrefInfo& gallery_info =
           galleries_info.find(pref_id)->second;
       const std::string& device_id = gallery_info.device_id;
       if (!ContainsKey(*attached_devices, device_id))
         continue;
 
       PrefIdFsInfoMap::const_iterator existing_info =
           pref_id_map_.find(pref_id);
       if (existing_info != pref_id_map_.end()) {
         result.push_back(existing_info->second);
-        new_galleries.insert(pref_id);
         continue;
       }
 
       base::FilePath path = gallery_info.AbsolutePath();
       if (!MediaStorageUtil::CanCreateFileSystem(device_id, path))
         continue;
 
       std::string fsid =
           file_system_context_->RegisterFileSystem(device_id, path);
       if (fsid.empty())
         continue;
 
       MediaFileSystemInfo new_entry(
           gallery_info.GetGalleryDisplayName(),
           path,
           fsid,
           pref_id,
           GetTransientIdForRemovableDeviceId(device_id),
           StorageInfo::IsRemovableDevice(device_id),
           StorageInfo::IsMediaDevice(device_id));
       result.push_back(new_entry);
-      new_galleries.insert(pref_id);
       pref_id_map_[pref_id] = new_entry;
     }
 
     if (result.size() == 0) {
       rph_refs_.Reset();
       CleanUp();
-    } else {
-      RevokeOldGalleries(new_galleries);
     }
 
+    DCHECK_EQ(pref_id_map_.size(), result.size());
     callback.Run(result);
   }
 
   std::string GetTransientIdForRemovableDeviceId(const std::string& device_id) {
     if (!StorageInfo::IsRemovableDevice(device_id))
       return std::string();
 
     return StorageMonitor::GetInstance()->GetTransientIdForDeviceId(device_id);
   }
 
@@ skipping 316 matching lines @@
   DCHECK_EQ(1U, erase_count);
   if (extension_hosts->second.empty()) {
     // When a profile has no ExtensionGalleriesHosts left, remove the
     // matching gallery-change-watcher since it is no longer needed. Leave the
     // |extension_hosts| entry alone, since it indicates the profile has been
     // previously used.
     MediaGalleriesPreferences* preferences = GetPreferences(profile);
     preferences->RemoveGalleryChangeObserver(this);
   }
 }