Reland Propagate OnNativeWidgetMove to delegate/observers, etc.

ui/views/widget/widget.cc

Index: ui/views/widget/widget.cc
diff --git a/ui/views/widget/widget.cc b/ui/views/widget/widget.cc
index bc0c75a2c0104de1cecf65e0c1c2ab405ae3d4d6..3f780b7b2c75d0ad29afe44c425b25cd458438ae 100644
--- a/ui/views/widget/widget.cc
+++ b/ui/views/widget/widget.cc
@@ -959,6 +959,11 @@ gfx::Size Widget::GetMaximumSize() {
   return non_client_view_ ? non_client_view_->GetMaximumSize() : gfx::Size();
 }
 
+void Widget::OnNativeWidgetMove() {
+  widget_delegate_->OnWidgetMove();
+  FOR_EACH_OBSERVER(Observer, observers_, OnWidgetMoved(this));
+}
+
 void Widget::OnNativeWidgetSizeChanged(const gfx::Size& new_size) {
   root_view_->SetSize(new_size);