Use std::tie() for operator< in ui/

ui/app_list/views/apps_grid_view.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 UI_APP_LIST_VIEWS_APPS_GRID_VIEW_H_
 #define UI_APP_LIST_VIEWS_APPS_GRID_VIEW_H_
 
 #include <set>
 #include <string>
+#include <tuple>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/timer/timer.h"
 #include "ui/app_list/app_list_export.h"
 #include "ui/app_list/app_list_model.h"
 #include "ui/app_list/app_list_model_observer.h"
 #include "ui/app_list/pagination_model.h"
 #include "ui/app_list/pagination_model_observer.h"
@@ skipping 216 matching lines @@
     Index() : page(-1), slot(-1) {}
     Index(int page, int slot) : page(page), slot(slot) {}
 
     bool operator==(const Index& other) const {
       return page == other.page && slot == other.slot;
     }
     bool operator!=(const Index& other) const {
       return page != other.page || slot != other.slot;
     }
     bool operator<(const Index& other) const {
-      if (page != other.page)
-        return page < other.page;
-
-      return slot < other.slot;
+      return std::tie(page, slot) < std::tie(other.page, other.slot);
     }
 
     int page;  // Which page an item view is on.
     int slot;  // Which slot in the page an item view is in.
   };
 
   int tiles_per_page() const { return cols_ * rows_per_page_; }
 
   // Updates from model.
   void Update();
@@ skipping 314 matching lines @@
 
   // True if the drag_view_ item is a folder item being dragged for reparenting.
   bool dragging_for_reparent_item_;
 
   DISALLOW_COPY_AND_ASSIGN(AppsGridView);
 };
 
 }  // namespace app_list
 
 #endif  // UI_APP_LIST_VIEWS_APPS_GRID_VIEW_H_