Fix a bug of PopupAlignmentDelegate on non-primary display

ash/common/system/web_notification/ash_popup_alignment_delegate.cc

 // Copyright 2014 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/web_notification/ash_popup_alignment_delegate.h"
 
 #include "ash/common/shelf/shelf_constants.h"
 #include "ash/common/shelf/wm_shelf.h"
 #include "ash/common/wm_root_window_controller.h"
 #include "ash/common/wm_shell.h"
@@ skipping 72 matching lines @@
   if (IsFromLeft())
     return work_area_.x() + kToastMarginX;
   return work_area_.right() - kToastMarginX - toast_bounds.width();
 }
 
 int AshPopupAlignmentDelegate::GetBaseLine() const {
   return work_area_.bottom() - kNoToastMarginBorderAndShadowOffset -
          tray_bubble_height_;
 }
 
-int AshPopupAlignmentDelegate::GetWorkAreaBottom() const {
-  return work_area_.bottom() - tray_bubble_height_;
+gfx::Rect AshPopupAlignmentDelegate::GetWorkArea() const {
+  gfx::Rect work_area_without_tray_bubble = work_area_;
+  work_area_without_tray_bubble.set_height(
+      work_area_without_tray_bubble.height() - tray_bubble_height_);
+  return work_area_without_tray_bubble;
 }
 
 bool AshPopupAlignmentDelegate::IsTopDown() const {
   return false;
 }
 
 bool AshPopupAlignmentDelegate::IsFromLeft() const {
   return GetAlignment() == SHELF_ALIGNMENT_LEFT;
 }
 
@@ skipping 48 matching lines @@
     const display::Display& old_display) {}
 
 void AshPopupAlignmentDelegate::OnDisplayMetricsChanged(
     const display::Display& display,
     uint32_t metrics) {
   if (GetCurrentDisplay().id() == display.id())
     UpdateWorkArea();
 }
 
 }  // namespace ash