Revert "Only alert accessibility when a notification's text changes"

This reverts commit feb758c3.

Reason for revert: <INSERT REASONING HERE>
SpokenFeedbackTests failing on chromeos dbg
Original change's description:
> Only alert accessibility when a notification's text changes
> 
> Bug: 867426
> Change-Id: I7f220566f3e7a2b4ce7ef639d012f4323b762208
> Reviewed-on: https://chromium-review.googlesource.com/1166231
> Reviewed-by: Steven Bennetts <stevenjb@chromium.org>
> Commit-Queue: David Tseng <dtseng@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#581474}

TBR=stevenjb@chromium.org,dtseng@chromium.org

Change-Id: I8b23c03e08642caa7b05d2ce88e6f330dd056c37
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 867426
Reviewed-on: https://chromium-review.googlesource.com/1167603Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#581607}

ui/message_center/views/message_popup_view.cc

@@ -65,17 +65,11 @@ MessagePopupView::MessagePopupView(PopupAlignmentDelegate* alignment_delegate,
 MessagePopupView::~MessagePopupView() = default;
 
 void MessagePopupView::UpdateContents(const Notification& notification) {
-  ui::AXNodeData old_data;
-  message_view_->GetAccessibleNodeData(&old_data);
   message_view_->UpdateWithNotification(notification);
   popup_collection_->NotifyPopupResized();
   if (notification.rich_notification_data()
           .should_make_spoken_feedback_for_popup_updates) {
-    ui::AXNodeData new_data;
-    message_view_->GetAccessibleNodeData(&new_data);
-    if (old_data.GetStringAttribute(ax::mojom::StringAttribute::kName) !=
-        new_data.GetStringAttribute(ax::mojom::StringAttribute::kName))
-      NotifyAccessibilityEvent(ax::mojom::Event::kAlert, true);
+    NotifyAccessibilityEvent(ax::mojom::Event::kAlert, true);
   }
 }