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

ui/app_list/views/apps_grid_view.h

Index: ui/app_list/views/apps_grid_view.h
diff --git a/ui/app_list/views/apps_grid_view.h b/ui/app_list/views/apps_grid_view.h
index d96d3490c35171619d7e365089ec9f53a33b9c39..814abf42cb47131418f29ca8e70365a1d61acd20 100644
--- a/ui/app_list/views/apps_grid_view.h
+++ b/ui/app_list/views/apps_grid_view.h
@@ -7,6 +7,7 @@
 
 #include <set>
 #include <string>
+#include <tuple>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
@@ -243,10 +244,7 @@ class APP_LIST_EXPORT AppsGridView : public views::View,
       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.