Implement clip and scroll DisplayItems for PartPainter

Source/core/paint/PartPainter.cpp

Index: Source/core/paint/PartPainter.cpp
diff --git a/Source/core/paint/PartPainter.cpp b/Source/core/paint/PartPainter.cpp
index 7885c125eeb875e13689b417ec8e5db70918e048..6ff60017973ea17ae80bbc9bfe936d7e3a813eb5 100644
--- a/Source/core/paint/PartPainter.cpp
+++ b/Source/core/paint/PartPainter.cpp
@@ -6,9 +6,11 @@
 #include "core/paint/PartPainter.h"
 
 #include "core/paint/BoxPainter.h"
-
 #include "core/paint/GraphicsContextAnnotator.h"
+#include "core/paint/RenderDrawingRecorder.h"
+#include "core/paint/RoundedInnerRectClipper.h"
 #include "core/paint/ScrollableAreaPainter.h"
+#include "core/paint/TransformRecorder.h"
 #include "core/rendering/PaintInfo.h"
 #include "core/rendering/RenderLayer.h"
 #include "core/rendering/RenderPart.h"
@@ -23,6 +25,7 @@ void PartPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffs
         return;
 
     LayoutPoint adjustedPaintOffset = paintOffset + m_renderPart.location();
+    LayoutRect borderRect(adjustedPaintOffset, m_renderPart.size());
 
     if (m_renderPart.hasBoxDecorationBackground() && (paintInfo.phase == PaintPhaseForeground || paintInfo.phase == PaintPhaseSelection))
         BoxPainter(m_renderPart).paintBoxDecorationBackground(paintInfo, adjustedPaintOffset);
@@ -33,35 +36,29 @@ void PartPainter::paint(const PaintInfo& paintInfo, const LayoutPoint& paintOffs
     }
 
     if ((paintInfo.phase == PaintPhaseOutline || paintInfo.phase == PaintPhaseSelfOutline) && m_renderPart.style()->hasOutline())
-        ObjectPainter(m_renderPart).paintOutline(paintInfo, LayoutRect(adjustedPaintOffset, m_renderPart.size()));
+        ObjectPainter(m_renderPart).paintOutline(paintInfo, borderRect);
 
     if (paintInfo.phase != PaintPhaseForeground)
         return;
 
+    OwnPtr<RoundedInnerRectClipper> clipper;
     if (m_renderPart.style()->hasBorderRadius()) {
-        LayoutRect borderRect = LayoutRect(adjustedPaintOffset, m_renderPart.size());
-
-        if (borderRect.isEmpty())
-            return;
-
-        // Push a clip if we have a border radius, since we want to round the foreground content that gets painted.
-        paintInfo.context->save();
         FloatRoundedRect roundedInnerRect = m_renderPart.style()->getRoundedInnerBorderFor(borderRect,
             m_renderPart.paddingTop() + m_renderPart.borderTop(), m_renderPart.paddingBottom() + m_renderPart.borderBottom(), m_renderPart.paddingLeft() + m_renderPart.borderLeft(), m_renderPart.paddingRight() + m_renderPart.borderRight(), true, true);
-        BoxPainter::clipRoundedInnerRect(paintInfo.context, borderRect, roundedInnerRect);
+        clipper = adoptPtr(new RoundedInnerRectClipper(m_renderPart, paintInfo, borderRect, roundedInnerRect, ApplyToDisplayListIfEnabled));
     }
 
     if (m_renderPart.widget())
         m_renderPart.paintContents(paintInfo, paintOffset);
-
-    if (m_renderPart.style()->hasBorderRadius())
-        paintInfo.context->restore();
+    clipper.clear();
 
     // Paint a partially transparent wash over selected widgets.
     if (m_renderPart.isSelected() && !m_renderPart.document().printing()) {
         LayoutRect rect = m_renderPart.localSelectionRect();
         rect.moveBy(adjustedPaintOffset);
-        paintInfo.context->fillRect(pixelSnappedIntRect(rect), m_renderPart.selectionBackgroundColor());
+        IntRect selectionRect = pixelSnappedIntRect(rect);
+        RenderDrawingRecorder recorder(paintInfo.context, m_renderPart, paintInfo.phase, selectionRect);
+        paintInfo.context->fillRect(selectionRect, m_renderPart.selectionBackgroundColor());
     }
 
     if (m_renderPart.canResize())
@@ -85,14 +82,9 @@ void PartPainter::paintContents(const PaintInfo& paintInfo, const LayoutPoint& p
     IntSize widgetPaintOffset = paintLocation - widgetLocation;
     // When painting widgets into compositing layers, tx and ty are relative to the enclosing compositing layer,
     // not the root. In this case, shift the CTM and adjust the paintRect to be root-relative to fix plug-in drawing.
-    if (!widgetPaintOffset.isZero()) {
-        paintInfo.context->translate(widgetPaintOffset.width(), widgetPaintOffset.height());
-        paintRect.move(-widgetPaintOffset);
-    }
+    TransformRecorder transform(*paintInfo.context, m_renderPart.displayItemClient(),
+        AffineTransform::translation(widgetPaintOffset.width(), widgetPaintOffset.height()));
     widget->paint(paintInfo.context, paintRect);
-
-    if (!widgetPaintOffset.isZero())
-        paintInfo.context->translate(-widgetPaintOffset.width(), -widgetPaintOffset.height());
 }
 
 } // namespace blink