Make the sort order in thumbnail view always alphabetical.

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

Index: ui/file_manager/file_manager/foreground/js/ui/list_container.js
diff --git a/ui/file_manager/file_manager/foreground/js/ui/list_container.js b/ui/file_manager/file_manager/foreground/js/ui/list_container.js
index 96bdbed10b3a5eef86141b6d2dda8bc5f032e63f..d9d3b798a5c4acac8b088779fdf458a105de360a 100644
--- a/ui/file_manager/file_manager/foreground/js/ui/list_container.js
+++ b/ui/file_manager/file_manager/foreground/js/ui/list_container.js
@@ -102,6 +102,14 @@ function ListContainer(element, table, grid) {
    */
   this.textSearchState = new TextSearchState();
 
+  /**
+   * Saved sort status of DETAIL view. This is used to restore sort order when
+   * the view is changed to DETAIL from THUMBNAIL, in which the sort order is
+   * always alphabetical.
+   * @type {!Object}
+   */
+  this.savedSortStatus_ = {};
+
   // Overriding the default role 'list' to 'listbox' for better accessibility
   // on ChromeOS.
   this.table.list.setAttribute('role', 'listbox');
@@ -193,6 +201,12 @@ ListContainer.prototype.setCurrentListType = function(listType) {
   // view that is not in use.
   switch (listType) {
     case ListContainer.ListType.DETAIL:
+      // Restore the last sort status of the detail view
+      if (this.savedSortStatus_) {
+        this.dataModel.sort(this.savedSortStatus_.field,
+                            this.savedSortStatus_.direction);
+      }
+
       this.table.dataModel = this.dataModel;
       this.table.selectionModel = this.selectionModel;
       this.table.hidden = false;
@@ -202,6 +216,12 @@ ListContainer.prototype.setCurrentListType = function(listType) {
       break;
 
     case ListContainer.ListType.THUMBNAIL:
+      // Save the last sort status of the detail view, and use alphabetical
+      // order for the thumbnail view.
+      if (this.dataModel.sortStatus.field)
+        this.savedSortStatus_ = this.dataModel.sortStatus;
+      this.dataModel.sort('name', 'asc');
+
       this.grid.dataModel = this.dataModel;
       this.grid.selectionModel = this.selectionModel;
       this.grid.hidden = false;
@@ -218,6 +238,34 @@ ListContainer.prototype.setCurrentListType = function(listType) {
 };
 
 /**
+ * Sets sorting order of this list container. Note that, whether the sort order
+ * of list container is applied to the list depends on the list type. If the
+ * list type is THUMBNAIL, the list will always be sorted in alphabetical order.
+ * The given sort order will be applied after the list type becomes DETAIL.
+ * @param {string} field
+ * @param {string} direction
+ */
+ListContainer.prototype.sort = function(field, direction) {
+  if (this.currentListType === ListContainer.ListType.DETAIL) {
+    this.dataModel.sort(field, direction);
+  } else {
+    this.savedSortStatus_ = {field: field, direction: direction};
+  }
+};
+
+/**
+ * Returns sort status, which is used to sort the file list in DETAIL view.
+ * @return {!Object}
+ */
+ListContainer.prototype.getSortStatus = function() {
+  if (this.currentListType === ListContainer.ListType.DETAIL) {
+    return this.dataModel.sortStatus;
+  } else {
+    return this.savedSortStatus_;
+  }
+};
+
+/**
  * Clears hover highlighting in the list container until next mouse move.
  */
 ListContainer.prototype.clearHover = function() {