Move SelectionTemplate::is_handle_visible_ to FrameSelection

This patch moves |is_handle_visible_| to |FrameSelection| from |SelectionTemplate|
since handle visibility is used only for setting |FrameSelection|, hence it is
a redundant member variable of |SelectionTemplate|.

Bug: 742093
Change-Id: I3add4da3844fb40be34dcb4d4b46b5fa6fed1d7e
Reviewed-on: https://chromium-review.googlesource.com/595389
Commit-Queue: Yoshifumi Inoue <yosin@chromium.org>
Reviewed-by: Xiaocheng Hu <xiaochengh@chromium.org>
Reviewed-by: Kent Tamura <tkent@chromium.org>
Cr-Commit-Position: refs/heads/master@{#491660}
LayoutRect FrameSelection::UnclippedBounds() const {
  LocalFrameView* view = frame_->View();
  LayoutViewItem layout_view = frame_->ContentLayoutItem();

  if (!view || layout_view.IsNull())
    return LayoutRect();

  view->UpdateLifecycleToLayoutClean();
  return LayoutRect(layout_selection_->SelectionBounds());
}

LayoutRect FrameSelection::UnclippedBounds() const {
  LocalFrameView* view = frame_->View();
  LayoutViewItem layout_view = frame_->ContentLayoutItem();

  if (!view || layout_view.IsNull())
    return LayoutRect();

  view->UpdateLifecycleToLayoutClean();
  return LayoutRect(layout_selection_->SelectionBounds());
}
