[LayoutNG] Update comment in ng_text_fragment_painter.cc

Bug: 708452
Cq-Include-Trybots: master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2
Change-Id: Iafc4c16aac974aa50bbd79960179ba17a3dff7cb
Reviewed-on: https://chromium-review.googlesource.com/821337Reviewed-by: Koji Ishii <kojii@chromium.org>
Commit-Queue: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523387}

third_party/WebKit/Source/core/paint/ng/ng_text_fragment_painter.cc

@@ -110,7 +110,7 @@ static void PaintSelection(GraphicsContext& context,
   context.FillRect(selection_rect, color);
 }
 
-// This is copied from InlineTextBoxPainter::PaintSelection() but lucks of
+// This is copied from InlineTextBoxPainter::PaintSelection() but lacks of
 // ltr, expanding new line wrap or so which uses InlineTextBox functions.
 void NGTextFragmentPainter::Paint(const Document& document,
                                   const PaintInfo& paint_info,
@@ -184,6 +184,7 @@ void NGTextFragmentPainter::Paint(const Document& document,
   // include selection and composition highlights.
   if (have_selection && paint_info.phase != PaintPhase::kSelection &&
       paint_info.phase != PaintPhase::kTextClip && !is_printing) {
+    // TODO(yoichio): Implement composition highlights.
     PaintSelection(context, text_fragment, document, style,
                    selection_style.fill_color, box_rect, selection_start,
                    selection_end);