[WIP][b:eae_mywip_paint] Paint Selection NG.

third_party/WebKit/Source/core/paint/NGBoxFragmentPainter.cpp

 // Copyright 2017 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/paint/NGBoxFragmentPainter.h"
 
 #include "core/layout/BackgroundBleedAvoidance.h"
 #include "core/layout/ng/inline/ng_physical_line_box_fragment.h"
 #include "core/layout/ng/inline/ng_physical_text_fragment.h"
 #include "core/layout/ng/ng_physical_box_fragment.h"
@@ skipping 26 matching lines @@
     }
   }
 }
 
 void NGBoxFragmentPainter::PaintLineBox(
     const NGPhysicalLineBoxFragment* fragment,
     const PaintInfo& paint_info,
     const LayoutPoint& paint_offset) {
   // TODO: Should this check if the line boxes intersects with the dirty rect
   // like legacy layout or do we want to change the invalidation logic?
+  if (DrawingRecorder::UseCachedDrawingIfPossible(

[kojii, 2017/06/16 11:25:57]

Can explain what this is?

+          paint_info.context, *fragment,
+          DisplayItem::PaintPhaseToDrawingType(paint_info.phase)))
+    return;
 
   LayoutRect overflow_rect(box_fragment_->VisualOverflowRect());
   overflow_rect.MoveBy(paint_offset);
 
   // TODO(eae): Should this go here, in ::Paint or in the NGTextFragmentPainter
   // class?
   DrawingRecorder recorder(
       paint_info.context, *fragment,
       DisplayItem::PaintPhaseToDrawingType(paint_info.phase),
       PixelSnappedIntRect(overflow_rect));
@@ skipping 419 matching lines @@
                                         include_logical_left_edge,
                                         include_logical_right_edge);
   border_painter.PaintBorder(info, rect);
 }
 
 const Document& NGBoxFragmentPainter::GetDocument() const {
   return box_fragment_->GetLayoutObject()->GetDocument();
 }
 
 }  // namespace blink