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}
void SelectionController::HandleMouseDraggedEvent(
    const MouseEventWithHitTestResults& event,
    const IntPoint& mouse_down_pos,
    const LayoutPoint& drag_start_pos,
    Node* mouse_press_node,
    const IntPoint& last_known_mouse_position) {
  TRACE_EVENT0("blink", "SelectionController::handleMouseDraggedEvent");

  if (!Selection().IsAvailable())
    return;
  if (selection_state_ != SelectionState::kExtendedSelection) {
    HitTestRequest request(HitTestRequest::kReadOnly | HitTestRequest::kActive);
    HitTestResult result(request, mouse_down_pos);
    frame_->GetDocument()->GetLayoutViewItem().HitTest(result);

    UpdateSelectionForMouseDrag(result, mouse_press_node, drag_start_pos,
                                last_known_mouse_position);
  }
  UpdateSelectionForMouseDrag(event.GetHitTestResult(), mouse_press_node,
                              drag_start_pos, last_known_mouse_position);
}

void SelectionController::HandleMouseDraggedEvent(
    const MouseEventWithHitTestResults& event,
    const IntPoint& mouse_down_pos,
    const LayoutPoint& drag_start_pos,
    Node* mouse_press_node,
    const IntPoint& last_known_mouse_position) {
  TRACE_EVENT0("blink", "SelectionController::handleMouseDraggedEvent");

  if (!Selection().IsAvailable())
    return;
  if (selection_state_ != SelectionState::kExtendedSelection) {
    HitTestRequest request(HitTestRequest::kReadOnly | HitTestRequest::kActive);
    HitTestResult result(request, mouse_down_pos);
    frame_->GetDocument()->GetLayoutViewItem().HitTest(result);

    UpdateSelectionForMouseDrag(result, mouse_press_node, drag_start_pos,
                                last_known_mouse_position);
  }
  UpdateSelectionForMouseDrag(event.GetHitTestResult(), mouse_press_node,
                              drag_start_pos, last_known_mouse_position);
}
