Implement a paint offset cache for slimming paint v2

Source/core/paint/TableCellPainter.cpp

 // Copyright 2014 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 "config.h"
 #include "core/paint/TableCellPainter.h"
 
 #include "core/layout/LayoutTableCell.h"
 #include "core/paint/BlockPainter.h"
 #include "core/paint/BoxPainter.h"
@@ skipping 94 matching lines @@
     LayoutRect paintRect = paintBounds(paintOffset, AddOffsetFromParent);
     IntRect borderRect = pixelSnappedIntRect(paintRect.x() - leftWidth / 2,
         paintRect.y() - topWidth / 2,
         paintRect.width() + leftWidth / 2 + (rightWidth + 1) / 2,
         paintRect.height() + topWidth / 2 + (bottomWidth + 1) / 2);
 
     if (!borderRect.intersects(paintInfo.rect))
         return;
 
     GraphicsContext* graphicsContext = paintInfo.context;
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*graphicsContext, m_layoutTableCell, static_cast<DisplayItem::Type>(displayItemType)))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*graphicsContext, m_layoutTableCell, static_cast<DisplayItem::Type>(displayItemType), paintOffset))
         return;
 
-    LayoutObjectDrawingRecorder recorder(*graphicsContext, m_layoutTableCell, static_cast<DisplayItem::Type>(displayItemType), borderRect);
+    LayoutObjectDrawingRecorder recorder(*graphicsContext, m_layoutTableCell, static_cast<DisplayItem::Type>(displayItemType), borderRect, paintOffset);
     Color cellColor = m_layoutTableCell.resolveColor(CSSPropertyColor);
     bool antialias = BoxPainter::shouldAntialiasLines(graphicsContext);
 
     // We never paint diagonals at the joins.  We simply let the border with the highest
     // precedence paint on top of borders with lower precedence.
     if (displayItemType & DisplayItem::TableCollapsedBorderTop) {
         ObjectPainter::drawLineForBoxSide(graphicsContext, borderRect.x(), borderRect.y(), borderRect.maxX(), borderRect.y() + topWidth, BSTop,
             topBorderValue.color().resolve(cellColor), collapsedBorderStyle(topBorderValue.style()), 0, 0, antialias);
     }
     if (displayItemType & DisplayItem::TableCollapsedBorderBottom) {
@@ skipping 51 matching lines @@
         return;
 
     LayoutTable* table = m_layoutTableCell.table();
     if (!table->collapseBorders() && m_layoutTableCell.style()->emptyCells() == HIDE && !m_layoutTableCell.firstChild())
         return;
 
     bool needsToPaintBorder = m_layoutTableCell.styleRef().hasBorderDecoration() && !table->collapseBorders();
     if (!m_layoutTableCell.hasBackground() && !m_layoutTableCell.styleRef().boxShadow() && !needsToPaintBorder)
         return;
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutTableCell, DisplayItem::BoxDecorationBackground))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutTableCell, DisplayItem::BoxDecorationBackground, paintOffset))
         return;
 
     LayoutRect visualOverflowRect = m_layoutTableCell.visualOverflowRect();
     visualOverflowRect.moveBy(paintOffset);
     // TODO(chrishtr): the pixel-snapping here is likely incorrect.
-    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutTableCell, DisplayItem::BoxDecorationBackground, pixelSnappedIntRect(visualOverflowRect));
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutTableCell, DisplayItem::BoxDecorationBackground, pixelSnappedIntRect(visualOverflowRect), paintOffset);
 
     LayoutRect paintRect = paintBounds(paintOffset, DoNotAddOffsetFromParent);
 
     BoxPainter::paintBoxShadow(paintInfo, paintRect, m_layoutTableCell.styleRef(), Normal);
 
     // Paint our cell background.
     paintBackgroundsBehindCell(paintInfo, paintOffset, &m_layoutTableCell);
 
     BoxPainter::paintBoxShadow(paintInfo, paintRect, m_layoutTableCell.styleRef(), Inset);
 
     if (!needsToPaintBorder)
         return;
 
     BoxPainter::paintBorder(m_layoutTableCell, paintInfo, paintRect, m_layoutTableCell.styleRef());
 }
 
 void TableCellPainter::paintMask(const PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
     if (m_layoutTableCell.style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
         return;
 
     LayoutTable* tableElt = m_layoutTableCell.table();
     if (!tableElt->collapseBorders() && m_layoutTableCell.style()->emptyCells() == HIDE && !m_layoutTableCell.firstChild())
         return;
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutTableCell, paintInfo.phase))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutTableCell, paintInfo.phase, paintOffset))
         return;
 
     LayoutRect paintRect = paintBounds(paintOffset, DoNotAddOffsetFromParent);
-    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutTableCell, paintInfo.phase, paintRect);
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutTableCell, paintInfo.phase, paintRect, paintOffset);
     BoxPainter(m_layoutTableCell).paintMaskImages(paintInfo, paintRect);
 }
 
 LayoutRect TableCellPainter::paintBounds(const LayoutPoint& paintOffset, PaintBoundOffsetBehavior paintBoundOffsetBehavior)
 {
     LayoutPoint adjustedPaintOffset = paintOffset;
     if (paintBoundOffsetBehavior == AddOffsetFromParent)
         adjustedPaintOffset.moveBy(m_layoutTableCell.location());
     return LayoutRect(adjustedPaintOffset, LayoutSize(m_layoutTableCell.pixelSnappedSize()));
 }
 
 } // namespace blink