ash: Move AppList support to ShelfWidget, expose ShelfWidget in WmShelf

ash/first_run/first_run_helper_impl.cc

 // Copyright 2013 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/first_run/first_run_helper_impl.h"
 
 #include "ash/common/shelf/app_list_button.h"
-#include "ash/common/shelf/shelf.h"
+#include "ash/common/shelf/shelf_widget.h"
+#include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/shell_window_ids.h"
 #include "ash/common/system/tray/system_tray.h"
+#include "ash/common/wm_lookup.h"
 #include "ash/shell.h"
 #include "base/logging.h"
 #include "ui/app_list/views/app_list_view.h"
 #include "ui/aura/window.h"
 #include "ui/display/display.h"
 #include "ui/display/screen.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/views/view.h"
 #include "ui/views/widget/widget.h"
 
@@ skipping 25 matching lines @@
   if (IsTrayBubbleOpened())
     CloseTrayBubble();
   widget_->Close();
 }
 
 views::Widget* FirstRunHelperImpl::GetOverlayWidget() {
   return widget_;
 }
 
 gfx::Rect FirstRunHelperImpl::GetAppListButtonBounds() {
-  Shelf* shelf = Shelf::ForPrimaryDisplay();
-  AppListButton* app_button = shelf->GetAppListButton();
+  WmShelf* shelf =
+      WmShelf::ForWindow(WmLookup::Get()->GetWindowForWidget(widget_));

[msw, 2016/08/29 22:58:08]

nit/q: Why look up widget_ instead of using WmShell::GetPrimaryRootWindow()?

[James Cook, 2016/08/29 23:49:25]

No particularly good reason. Switched to WmShell::GetPrimaryRootWindow().

+  AppListButton* app_button = shelf->shelf_widget()->GetAppListButton();
   return app_button->GetBoundsInScreen();
 }
 
 void FirstRunHelperImpl::Cancel() {
   FOR_EACH_OBSERVER(Observer, observers(), OnCancelled());
 }
 
 bool FirstRunHelperImpl::IsCancelingKeyEvent(ui::KeyEvent* event) {
   return event->key_code() == ui::VKEY_ESCAPE;
 }
@@ skipping 24 matching lines @@
   return bubble->GetBoundsInScreen();
 }
 
 gfx::Rect FirstRunHelperImpl::GetHelpButtonBounds() {
   SystemTray* tray = Shell::GetInstance()->GetPrimarySystemTray();
   views::View* help_button = tray->GetHelpButtonView();
   return help_button->GetBoundsInScreen();
 }
 
 }  // namespace ash