Implement a paint offset cache for slimming paint v2

Source/core/paint/FieldsetPainter.cpp

Index: Source/core/paint/FieldsetPainter.cpp
diff --git a/Source/core/paint/FieldsetPainter.cpp b/Source/core/paint/FieldsetPainter.cpp
index 57637952fbbcd48e700da2fbce622e4abff8c94a..b2ced4aa7764744b6f57d9e0ee70f72d18ec824a 100644
--- a/Source/core/paint/FieldsetPainter.cpp
+++ b/Source/core/paint/FieldsetPainter.cpp
@@ -24,7 +24,7 @@ void FieldsetPainter::paintBoxDecorationBackground(const PaintInfo& paintInfo, c
     if (!legend)
         return BoxPainter(m_layoutFieldset).paintBoxDecorationBackground(paintInfo, paintOffset);
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutFieldset, paintInfo.phase))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutFieldset, paintInfo.phase, paintOffset))
         return;
 
     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
@@ -41,7 +41,7 @@ void FieldsetPainter::paintBoxDecorationBackground(const PaintInfo& paintInfo, c
     }
 
     // TODO(chrishtr): pixel-snapping here is likely wrong.
-    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutFieldset, paintInfo.phase, paintRect);
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutFieldset, paintInfo.phase, paintRect, paintOffset);
     BoxDecorationData boxDecorationData(m_layoutFieldset);
 
     if (boxDecorationData.bleedAvoidance == BackgroundBleedNone)
@@ -82,7 +82,7 @@ void FieldsetPainter::paintMask(const PaintInfo& paintInfo, const LayoutPoint& p
     if (!legend)
         return BoxPainter(m_layoutFieldset).paintMask(paintInfo, paintOffset);
 
-    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutFieldset, paintInfo.phase))
+    if (LayoutObjectDrawingRecorder::useCachedDrawingIfPossible(*paintInfo.context, m_layoutFieldset, paintInfo.phase, paintOffset))
         return;
 
     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
@@ -98,7 +98,7 @@ void FieldsetPainter::paintMask(const PaintInfo& paintInfo, const LayoutPoint& p
         paintRect.move(xOff, 0);
     }
 
-    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutFieldset, paintInfo.phase, paintRect);
+    LayoutObjectDrawingRecorder recorder(*paintInfo.context, m_layoutFieldset, paintInfo.phase, paintRect, paintOffset);
     BoxPainter(m_layoutFieldset).paintMaskImages(paintInfo, paintRect);
 }