Retain popup bubble mouse status even through updates.

ui/message_center/views/message_view.cc

Index: ui/message_center/views/message_view.cc
diff --git a/ui/message_center/views/message_view.cc b/ui/message_center/views/message_view.cc
index 1783533b2d625248e73f88fd7c8f526bbd9918b3..11ff5485f86612ed4314d70b68a786060404df56 100644
--- a/ui/message_center/views/message_view.cc
+++ b/ui/message_center/views/message_view.cc
@@ -83,6 +83,11 @@ MessageView::MessageView(MessageViewController* controller,
 MessageView::~MessageView() {
 }
 
+void MessageView::UpdateWithNotification(const Notification& notification) {
+  small_image_view_->SetImage(notification.small_image().AsImageSkia());
+  display_source_ = notification.display_source();
+}
+
 // static
 gfx::Insets MessageView::GetShadowInsets() {
   return gfx::Insets(kShadowBlur / 2 - kShadowOffset,