Start removing some pre-md constants and related code.

ash/common/system/status_area_widget_delegate.cc

 // 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.
 
 #include "ash/common/system/status_area_widget_delegate.h"
 
 #include "ash/ash_export.h"
 #include "ash/common/focus_cycler.h"
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/shelf/shelf_constants.h"
@@ skipping 128 matching lines @@
     views::View* child = child_at(c);
     if (!child->visible())
       continue;
     SetBorderOnChild(child, is_child_on_edge);
     is_child_on_edge = false;
   }
 
   views::ColumnSet* columns = layout->AddColumnSet(0);
 
   if (IsHorizontalAlignment(alignment_)) {
-    bool is_first_visible_child = true;
     for (int c = child_count() - 1; c >= 0; --c) {
       views::View* child = child_at(c);
       if (!child->visible())
         continue;
-      if (!is_first_visible_child)
-        columns->AddPaddingColumn(0, GetTrayConstant(TRAY_SPACING));
-      is_first_visible_child = false;
       columns->AddColumn(views::GridLayout::CENTER, views::GridLayout::FILL,
                          0, /* resize percent */
                          views::GridLayout::USE_PREF, 0, 0);
     }
     layout->StartRow(0, 0);
     for (int c = child_count() - 1; c >= 0; --c) {
       views::View* child = child_at(c);
       if (child->visible())
         layout->AddView(child);
     }
   } else {
     columns->AddColumn(views::GridLayout::FILL, views::GridLayout::CENTER,
                        0, /* resize percent */
                        views::GridLayout::USE_PREF, 0, 0);
-    bool is_first_visible_child = true;
     for (int c = child_count() - 1; c >= 0; --c) {
       views::View* child = child_at(c);
       if (!child->visible())
         continue;
-      if (!is_first_visible_child)
-        layout->AddPaddingRow(0, GetTrayConstant(TRAY_SPACING));
-      is_first_visible_child = false;
       layout->StartRow(0, 0);
       layout->AddView(child);
     }
   }
 
   layer()->GetAnimator()->StopAnimating();
   StatusAreaWidgetDelegateAnimationSettings settings(layer());
 
   Layout();
   UpdateWidgetSize();
@@ skipping 59 matching lines @@
   }
   child->SetBorder(
       views::CreateEmptyBorder(top_edge, left_edge, bottom_edge, right_edge));
   // Layout on |child| needs to be updated based on new border value before
   // displaying; otherwise |child| will be showing with old border size.
   // Fix for crbug.com/623438.
   child->Layout();
 }
 
 }  // namespace ash