Turn FrameView's paintBehavior into a real global

Source/core/paint/PaintPhase.h

Index: Source/core/paint/PaintPhase.h
diff --git a/Source/core/paint/PaintPhase.h b/Source/core/paint/PaintPhase.h
index df3be5b860519d1c4b1e5b363599c48ac5de856b..b9c29d28d08ccc66508694ac79a4f65cdbb9506d 100644
--- a/Source/core/paint/PaintPhase.h
+++ b/Source/core/paint/PaintPhase.h
@@ -57,8 +57,6 @@ enum PaintPhase {
 
 enum PaintBehaviorFlags {
     PaintBehaviorNormal = 0,
-    PaintBehaviorSelectionOnly = 1 << 0,
-    PaintBehaviorFlattenCompositingLayers = 1 << 2,
     PaintBehaviorRenderingClipPathAsMask = 1 << 3,
     PaintBehaviorSkipRootBackground = 1 << 4,
     PaintBehaviorRootBackgroundOnly = 1 << 5
@@ -66,6 +64,26 @@ enum PaintBehaviorFlags {
 
 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