Turn FrameView's paintBehavior into a real global

Source/core/paint/BoxPainter.cpp

Index: Source/core/paint/BoxPainter.cpp
diff --git a/Source/core/paint/BoxPainter.cpp b/Source/core/paint/BoxPainter.cpp
index 48959e689b285106da57c3e8120b39781108404b..513250a02d20e65bac3437b9f009896a95f0b196 100644
--- a/Source/core/paint/BoxPainter.cpp
+++ b/Source/core/paint/BoxPainter.cpp
@@ -525,7 +525,7 @@ void BoxPainter::paintMaskImages(const PaintInfo& paintInfo, const LayoutRect& p
     // Figure out if we need to push a transparency layer to render our mask.
     bool pushTransparencyLayer = false;
     bool compositedMask = m_layoutBox.hasLayer() && m_layoutBox.layer()->hasCompositedMask();
-    bool flattenCompositingLayers = m_layoutBox.view()->frameView() && m_layoutBox.view()->frameView()->paintBehavior() & PaintBehaviorFlattenCompositingLayers;
+    bool flattenCompositingLayers = gGlobalPaintFlags & GlobalPaintFlattenCompositingLayers;
 
     bool allMaskImagesLoaded = true;
 
@@ -770,7 +770,7 @@ bool BoxPainter::fixedBackgroundPaintsInLocalCoordinates(const LayoutObject& obj
 
     const LayoutView& view = toLayoutView(obj);
 
-    if (view.frameView() && view.frameView()->paintBehavior() & PaintBehaviorFlattenCompositingLayers)
+    if (gGlobalPaintFlags & GlobalPaintFlattenCompositingLayers)
         return false;
 
     DeprecatedPaintLayer* rootLayer = view.layer();