Separate the logic of popup alignment and workarea handling as delegate.

ui/message_center/views/toast_contents_view.cc

Index: ui/message_center/views/toast_contents_view.cc
diff --git a/ui/message_center/views/toast_contents_view.cc b/ui/message_center/views/toast_contents_view.cc
index e5de6a25100c74819a47c1c778258d65061c7a75..365519a920d0bbfd873f6fb33cf16490b1310f4e 100644
--- a/ui/message_center/views/toast_contents_view.cc
+++ b/ui/message_center/views/toast_contents_view.cc
@@ -246,9 +246,7 @@ void ToastContentsView::OnDisplayChanged() {
     return;
 
   collection_->OnDisplayMetricsChanged(
-      Screen::GetScreenFor(native_view)->GetDisplayNearestWindow(native_view),
-      gfx::DisplayObserver::DISPLAY_METRIC_BOUNDS |
-          gfx::DisplayObserver::DISPLAY_METRIC_WORK_AREA);
+      Screen::GetScreenFor(native_view)->GetDisplayNearestWindow(native_view));
 }
 
 void ToastContentsView::OnWorkAreaChanged() {
@@ -261,8 +259,7 @@ void ToastContentsView::OnWorkAreaChanged() {
     return;
 
   collection_->OnDisplayMetricsChanged(
-      Screen::GetScreenFor(native_view)->GetDisplayNearestWindow(native_view),
-      gfx::DisplayObserver::DISPLAY_METRIC_WORK_AREA);
+      Screen::GetScreenFor(native_view)->GetDisplayNearestWindow(native_view));
 }
 
 // views::View