Do not auto-select the first file on entering a folder.

chrome/browser/resources/file_manager/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 724 matching lines @@
                                  this.compareType_.bind(this));
 
     dataModel.addEventListener('splice',
                                this.onDataModelSplice_.bind(this));
     dataModel.addEventListener('permuted',
                                this.onDataModelPermuted_.bind(this));
 
     this.directoryModel_.getFileListSelection().addEventListener(
         'change', this.onSelectionChanged_.bind(this));
 
-    this.directoryModel_.setAutoSelectIndex(
-        this.dialogType_ == FileManager.DialogType.SELECT_SAVEAS_FILE ? -1 : 0);
-
     this.initTable_();
     this.initGrid_();
     this.initRootsList_();
 
     var listType = FileManager.ListType.DETAIL;
     if (FileManager.DialogType.isModal(this.dialogType_))
       listType = window.localStorage['listType-' + this.dialogType_] ||
           FileManager.ListType.DETAIL;
     this.setListType(listType);
 
@@ skipping 3573 matching lines @@
 
       handleSplitterDragEnd: function(e) {
         Splitter.prototype.handleSplitterDragEnd.apply(this, arguments);
         this.ownerDocument.documentElement.classList.remove('col-resize');
       }
     };
 
     customSplitter.decorate(splitterElement);
   };
 })();