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

ui/message_center/views/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 "ui/message_center/views/popup_alignment_delegate.h"
+
+#include "ui/message_center/views/message_popup_collection.h"
+
+namespace message_center {
+
+PopupAlignmentDelegate::PopupAlignmentDelegate() : collection_(NULL) {}
+
+PopupAlignmentDelegate::~PopupAlignmentDelegate() {}
+
+void PopupAlignmentDelegate::DoUpdateIfPossible() {
+  if (collection_)
+    collection_->DoUpdateIfPossible();
+}
+
+}  // namespace message_center