Update comment for SavePackageFilePickerChromeOS irregularity

chrome/browser/download/chrome_download_manager_delegate.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/download/chrome_download_manager_delegate.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 301 matching lines @@
 }
 
 void ChromeDownloadManagerDelegate::ChooseSavePath(
     WebContents* web_contents,
     const FilePath& suggested_path,
     const FilePath::StringType& default_extension,
     bool can_save_as_complete,
     content::SaveFilePathPickedCallback callback) {
   // Deletes itself.
 #if defined(OS_CHROMEOS)
-  // Note that we're ignoring the callback here. TODO(achuith): Fix this.
+  // Note that we're ignoring the callback here.
+  // SavePackageFilePickerChromeOS completes the save operation itself.
+  // TODO(achuith): Fix this.
   new SavePackageFilePickerChromeOS(web_contents, suggested_path);
 #else
   new SavePackageFilePicker(web_contents, suggested_path, default_extension,
       can_save_as_complete, download_prefs_.get(), callback);
 #endif
 }
 
 #if defined(ENABLE_SAFE_BROWSING)
 DownloadProtectionService*
     ChromeDownloadManagerDelegate::GetDownloadProtectionService() {
@@ skipping 306 matching lines @@
     int32 download_id, int64 db_handle) {
   // It's not immediately obvious, but HistoryBackend::CreateDownload() can
   // call this function with an invalid |db_handle|. For instance, this can
   // happen when the history database is offline. We cannot have multiple
   // DownloadItems with the same invalid db_handle, so we need to assign a
   // unique |db_handle| here.
   if (db_handle == DownloadItem::kUninitializedHandle)
     db_handle = download_history_->GetNextFakeDbHandle();
   download_manager_->OnItemAddedToPersistentStore(download_id, db_handle);
 }