Consolidate some more ash tray constants.

ash/common/system/tray/tray_utils.cc

Index: ash/common/system/tray/tray_utils.cc
diff --git a/ash/common/system/tray/tray_utils.cc b/ash/common/system/tray/tray_utils.cc
index 752394e822b6e86202c9312d1caf556a13ca5d25..62e8c34402b3d1fbd78058f74b83cd60a21a62a2 100644
--- a/ash/common/system/tray/tray_utils.cc
+++ b/ash/common/system/tray/tray_utils.cc
@@ -41,7 +41,7 @@ void SetTrayImageItemBorder(views::View* tray_view, ShelfAlignment alignment) {
   if (MaterialDesignController::IsShelfMaterial())
     return;
 
-  const int tray_image_item_padding = GetTrayConstant(TRAY_IMAGE_ITEM_PADDING);
+  const int tray_image_item_padding = kTrayImageItemPadding;

[tdanderson, 2017/02/28 17:08:18]

nit: local variable no longer needed, just use the constant itself in its place

[Evan Stade, 2017/03/01 04:28:54]

Done.

   if (IsHorizontalAlignment(alignment)) {
     tray_view->SetBorder(views::CreateEmptyBorder(0, tray_image_item_padding, 0,
                                                   tray_image_item_padding));