Implement interfaces in PaintInfo and make it a class.

Source/core/rendering/RenderFieldset.cpp

Index: Source/core/rendering/RenderFieldset.cpp
diff --git a/Source/core/rendering/RenderFieldset.cpp b/Source/core/rendering/RenderFieldset.cpp
index 291c6862c74158da54c46e8ed24b90adbce8d4e6..260eec0334927b2abe333ab2b452e45801b13d94 100644
--- a/Source/core/rendering/RenderFieldset.cpp
+++ b/Source/core/rendering/RenderFieldset.cpp
@@ -158,7 +158,7 @@ void RenderFieldset::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint
         paintRect.setX(paintRect.x() + xOff);
     }
 
-    if (!boxShadowShouldBeAppliedToBackground(determineBackgroundBleedAvoidance(paintInfo.context)))
+    if (!boxShadowShouldBeAppliedToBackground(determineBackgroundBleedAvoidance(paintInfo.getContext())))
         paintBoxShadow(paintInfo, paintRect, style(), Normal);
     paintFillLayers(paintInfo, resolveColor(CSSPropertyBackgroundColor), style()->backgroundLayers(), paintRect);
     paintBoxShadow(paintInfo, paintRect, style(), Inset);
@@ -167,7 +167,7 @@ void RenderFieldset::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint
         return;
 
     // Create a clipping region around the legend and paint the border as normal
-    GraphicsContext* graphicsContext = paintInfo.context;
+    GraphicsContext* graphicsContext = paintInfo.getContext();
     GraphicsContextStateSaver stateSaver(*graphicsContext);
 
     // FIXME: We need to work with "rl" and "bt" block flow directions.  In those
@@ -188,7 +188,7 @@ void RenderFieldset::paintBoxDecorations(PaintInfo& paintInfo, const LayoutPoint
 
 void RenderFieldset::paintMask(PaintInfo& paintInfo, const LayoutPoint& paintOffset)
 {
-    if (style()->visibility() != VISIBLE || paintInfo.phase != PaintPhaseMask)
+    if (style()->visibility() != VISIBLE || paintInfo.getPhase() != PaintPhaseMask)
         return;
 
     LayoutRect paintRect = LayoutRect(paintOffset, size());