Retrieve pinned flag directly from Notification class

ui/message_center/views/custom_notification_view.cc

 // Copyright 2016 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/custom_notification_view.h"
 
 #include <algorithm>
 
 #include "ui/base/ime/input_method.h"
 #include "ui/base/ime/text_input_client.h"
@@ skipping 57 matching lines @@
   if (!contents_view_delegate_)
     return false;
   return contents_view_delegate_->IsCloseButtonFocused();
 }
 
 void CustomNotificationView::RequestFocusOnCloseButton() {
   if (contents_view_delegate_)
     contents_view_delegate_->RequestFocusOnCloseButton();
 }
 
-bool CustomNotificationView::IsPinned() const {
-  if (!contents_view_delegate_)
-    return false;
-  return contents_view_delegate_->IsPinned();
-}
-
 const char* CustomNotificationView::GetClassName() const {
   return kViewClassName;
 }
 
 void CustomNotificationView::UpdateControlButtonsVisibility() {
   if (contents_view_delegate_)
     contents_view_delegate_->UpdateControlButtonsVisibility();
 }
 
 gfx::Size CustomNotificationView::GetPreferredSize() const {
@@ skipping 64 matching lines @@
 
 bool CustomNotificationView::OnMousePressed(const ui::MouseEvent& event) {
   // TODO(yhanada): This hack will be removed when HandleAccessibleAction will
   // be used for handling click events.
   if (contents_view_ && contents_view_->OnMousePressed(event))
     return true;
   return MessageView::OnMousePressed(event);
 }
 
 }  // namespace message_center