Turn FrameView's paintBehavior into a real global

Source/core/paint/PaintPhase.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  *           (C) 2000 Antti Koivisto (koivisto@kde.org)
  *           (C) 2000 Dirk Mueller (mueller@kde.org)
  *           (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ skipping 39 matching lines @@
     PaintPhaseCollapsedTableBorders = 9,
     PaintPhaseTextClip = 10,
     PaintPhaseMask = 11,
     PaintPhaseClippingMask = 12,
     PaintPhaseMax = PaintPhaseClippingMask,
     // These values must be kept in sync with DisplayItem::Type and DisplayItem::typeAsDebugString().
 };
 
 enum PaintBehaviorFlags {
     PaintBehaviorNormal = 0,
-    PaintBehaviorSelectionOnly = 1 << 0,
-    PaintBehaviorFlattenCompositingLayers = 1 << 2,
     PaintBehaviorRenderingClipPathAsMask = 1 << 3,
     PaintBehaviorSkipRootBackground = 1 << 4,
     PaintBehaviorRootBackgroundOnly = 1 << 5
 };
 
 typedef unsigned PaintBehavior;
 
+// Those flags are meant as global tree operations. This means
+// that they should be constant for a paint phase.
+// TODO(jchaffraix): We should pass these as a const variable
+// during paint to ensure they are not modified.
+enum GlobalPaintFlag {
+    GlobalPaintNormalPhase = 0,
+    // Used when painting selection as part of a drag-image. This
+    // flag disables a lot of the painting code and specifically
+    // triggers a PaintPhaseSelection.
+    GlobalPaintSelectionOnly = 1 << 0,
+    // Used when painting a drag-image or printing in order to
+    // ignore the hardware layers and paint the whole tree
+    // into the topmost layer.
+    GlobalPaintFlattenCompositingLayers = 1 << 1
+};
+
+typedef unsigned GlobalPaintFlags;
+
+extern GlobalPaintFlags gGlobalPaintFlags;
+
 } // namespace blink
 
 #endif // PaintPhase_h