(Merge to M-51) Revise the shelf alignment locking mechanism.

ash/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/system/status_area_widget_delegate.h"
 
 #include "ash/ash_export.h"
 #include "ash/ash_switches.h"
 #include "ash/focus_cycler.h"
+#include "ash/shelf/shelf_util.h"
 #include "ash/shell.h"
 #include "ash/shell_window_ids.h"
 #include "ash/system/tray/tray_constants.h"
 #include "base/strings/utf_string_conversions.h"
 #include "ui/aura/window_event_dispatcher.h"
 #include "ui/compositor/layer.h"
 #include "ui/compositor/scoped_layer_animation_settings.h"
 #include "ui/gfx/animation/tween.h"
 #include "ui/gfx/canvas.h"
 #include "ui/gfx/image/image.h"
@@ skipping 85 matching lines @@
   UpdateLayout();
 }
 
 void StatusAreaWidgetDelegate::UpdateLayout() {
   // Use a grid layout so that the trays can be centered in each cell, and
   // so that the widget gets laid out correctly when tray sizes change.
   views::GridLayout* layout = new views::GridLayout(this);
   SetLayoutManager(layout);
 
   views::ColumnSet* columns = layout->AddColumnSet(0);
-  if (alignment_ == SHELF_ALIGNMENT_BOTTOM) {
+  if (IsHorizontalAlignment(alignment_)) {
     bool is_first_visible_child = true;
     for (int c = 0; c < child_count(); ++c) {
       views::View* child = child_at(c);
       if (!child->visible())
         continue;
       if (!is_first_visible_child)
         columns->AddPaddingColumn(0, kTraySpacing);
       is_first_visible_child = false;
       columns->AddColumn(views::GridLayout::CENTER, views::GridLayout::FILL,
                          0, /* resize percent */
@@ skipping 38 matching lines @@
 void StatusAreaWidgetDelegate::ChildVisibilityChanged(View* child) {
   UpdateLayout();
 }
 
 void StatusAreaWidgetDelegate::UpdateWidgetSize() {
   if (GetWidget())
     GetWidget()->SetSize(GetPreferredSize());
 }
 
 }  // namespace ash