[Autofill] Remove AutofillPopupViewViews and associated feature.

Bug: 906135,831603
Change-Id: I3c982f8b3ffb4928c7c878e74e10113999106499
Reviewed-on: https://chromium-review.googlesource.com/c/1387124
Reviewed-by: Robert Kaplow <rkaplow@chromium.org>
Reviewed-by: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Fabio Tirelo <ftirelo@chromium.org>
Reviewed-by: Tommy Martino <tmartino@chromium.org>
Commit-Queue: Mathieu Perreault <mathp@chromium.org>
Cr-Commit-Position: refs/heads/master@{#621360}
AutofillPopupView* AutofillPopupView::Create(
    AutofillPopupController* controller) {
#if defined(OS_MACOSX)
  if (!platform_util::GetTopLevel(controller->container_view()))
    return nullptr;
#endif

  views::Widget* observing_widget =
      views::Widget::GetTopLevelWidgetForNativeView(
          controller->container_view());

#if !defined(OS_MACOSX)
  if (!observing_widget)
    return nullptr;
#endif

  if (features::ShouldUseNativeViews())
    return new AutofillPopupViewNativeViews(controller, observing_widget);

  return new AutofillPopupViewViews(controller, observing_widget);
}

AutofillPopupView* AutofillPopupView::Create(
    AutofillPopupController* controller) {
#if defined(OS_MACOSX)
  if (!platform_util::GetTopLevel(controller->container_view()))
    return nullptr;
#endif

  views::Widget* observing_widget =
      views::Widget::GetTopLevelWidgetForNativeView(
          controller->container_view());

#if !defined(OS_MACOSX)
  if (!observing_widget)
    return nullptr;
#endif

  if (features::ShouldUseNativeViews())
    return new AutofillPopupViewNativeViews(controller, observing_widget);

  return new AutofillPopupViewViews(controller, observing_widget);
}
