Shrink space required by history log file

ui/file_manager/file_manager/foreground/js/file_manager.js

 // 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.
 
 /**
  * FileManager constructor.
  *
  * FileManager objects encapsulate the functionality of the file selector
  * dialogs, as well as the full screen file manager application (though the
  * latter is not yet implemented).
@@ skipping 789 matching lines @@
 
   /**
    * Handles events when import history changed.
    *
    * @param {!importer.ImportHistory.ChangedEvent} event
    * @private
    */
   FileManager.prototype.onHistoryChanged_ = function(event) {
     this.tracker_.send(metrics.ImportEvents.HISTORY_CHANGED);
 
+    if (!event.entry) {

[mtomasz, 2015/02/25 00:40:17]

nit: Can we add a comment when can it happen that entry is not passed?

[Steve McKay, 2015/02/25 01:51:56]

Actually it should never be null. I might have added this when investigating
other issues. If we see problems in the future, we'll revisit adding
protections. For now, reverted.

+      return;
+    }
+
     // Ignore any entry that isn't an immediate child of the
     // current directory.
     util.isChildEntry(event.entry, this.getCurrentDirectoryEntry())
         .then(
             /**
              * @param {boolean} isChild
              * @this {FileManager}
              */
             function(isChild) {
               if (isChild) {
@@ skipping 481 matching lines @@
       out += this.initializeQueue_.pendingTasks[key].toString() + '\n';
     }.bind(this));
 
     out += '2. VolumeManagerWrapper\n' +
         this.volumeManager_.toString() + '\n';
 
     out += 'End of debug information.';
     console.log(out);
   };
 })();