Pass shelf instances, not root windows, for ash context menus.

ash/shell.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/shell.h"
 
 #include <algorithm>
 #include <string>
 #include <utility>
 
@@ skipping 505 matching lines @@
 
 ShelfAutoHideBehavior Shell::GetShelfAutoHideBehavior(
     aura::Window* root_window) const {
   ShelfWidget* shelf_widget = GetRootWindowController(root_window)->shelf();
   return shelf_widget->shelf_layout_manager()->auto_hide_behavior();
 }
 
 void Shell::SetShelfAlignment(ShelfAlignment alignment,
                               aura::Window* root_window) {
   ShelfWidget* shelf_widget = GetRootWindowController(root_window)->shelf();
-  if (shelf_widget->shelf_layout_manager()->SetAlignment(alignment)) {
-    FOR_EACH_OBSERVER(
-        ShellObserver, observers_, OnShelfAlignmentChanged(root_window));
-  }
+  shelf_widget->shelf_layout_manager()->SetAlignment(alignment);
 }
 
-ShelfAlignment Shell::GetShelfAlignment(const aura::Window* root_window) {
+ShelfAlignment Shell::GetShelfAlignment(const aura::Window* root_window) const {
   ShelfWidget* shelf_widget = GetRootWindowController(root_window)->shelf();
   return shelf_widget->shelf_layout_manager()->GetAlignment();
 }
 
+void Shell::OnShelfAlignmentChanged(aura::Window* root_window) {
+  FOR_EACH_OBSERVER(ShellObserver, observers_,
+                    OnShelfAlignmentChanged(root_window));
+}
+
 void Shell::NotifyFullscreenStateChange(bool is_fullscreen,
                                         aura::Window* root_window) {
   FOR_EACH_OBSERVER(ShellObserver, observers_, OnFullscreenStateChanged(
       is_fullscreen, root_window));
 }
 
 void Shell::CreateModalBackground(aura::Window* window) {
   if (!modality_filter_) {
     modality_filter_.reset(new SystemModalContainerEventFilter(this));
     AddPreTargetHandler(modality_filter_.get());
@@ skipping 657 matching lines @@
 
 void Shell::OnWindowActivated(
     aura::client::ActivationChangeObserver::ActivationReason reason,
     aura::Window* gained_active,
     aura::Window* lost_active) {
   if (gained_active)
     target_root_window_ = gained_active->GetRootWindow();
 }
 
 }  // namespace ash