Regularize ownerships and lifecycle for storage monitor platform classes.

chrome/browser/storage_monitor/storage_monitor.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_STORAGE_MONITOR_STORAGE_MONITOR_H_
 #define CHROME_BROWSER_STORAGE_MONITOR_STORAGE_MONITOR_H_
 
 #include "base/callback.h"
 #include "base/files/file_path.h"
 #include "base/observer_list_threadsafe.h"
 #include "base/string16.h"
 #include "base/synchronization/lock.h"
 
 class ChromeBrowserMainPartsLinux;
 class ChromeBrowserMainPartsMac;
 class MediaGalleriesPrivateApiTest;
 class MediaGalleriesPrivateEjectApiTest;
 
 namespace chrome {
 
 class MediaFileSystemRegistryTest;
 class RemovableStorageObserver;
 class TransientDeviceIds;
 
 // Base class for platform-specific instances watching for removable storage
 // attachments/detachments.
+// Lifecycle contracts: This class is created by ChromeBrowserMain
+// implementations before the profile is initialized, so listeners can be
+// created during profile construction. The platform-specific initialization,
+// which can lead to calling registered listeners with notifications of
+// attached volumes, will happen after profile construction.
 class StorageMonitor {
  public:
   struct StorageInfo {
     StorageInfo();
     StorageInfo(const std::string& id,
                 const string16& device_name,
                 const base::FilePath::StringType& device_location);
     ~StorageInfo();
 
     // Unique device id - persists between device attachments.
@@ skipping 123 matching lines @@
 
   // Map of all the attached removable storage devices.
   RemovableStorageMap storage_map_;
 
   scoped_ptr<TransientDeviceIds> transient_device_ids_;
 };
 
 } // namespace chrome
 
 #endif  // CHROME_BROWSER_STORAGE_MONITOR_STORAGE_MONITOR_H_