Add a paint filter utility canvas (SkPaintFilterCanvas)

src/utils/debugger/SkDebugCanvas.h

Index: src/utils/debugger/SkDebugCanvas.h
diff --git a/src/utils/debugger/SkDebugCanvas.h b/src/utils/debugger/SkDebugCanvas.h
index 5771dd9a744cd1b787f9a78c30730813361d8b2c..f6ef508623136f68f5e06eb4042522f7ac4481ad 100644
--- a/src/utils/debugger/SkDebugCanvas.h
+++ b/src/utils/debugger/SkDebugCanvas.h
@@ -17,7 +17,7 @@
 #include "SkTArray.h"
 #include "SkString.h"
 
-class SkTexOverrideFilter;
+class SkNWayCanvas;
 
 class SK_API SkDebugCanvas : public SkCanvas {
 public:
@@ -32,7 +32,7 @@ public:
     /**
      * Enable or disable overdraw visualization
      */
-    void setOverdrawViz(bool overdrawViz) { fOverdrawViz = overdrawViz; }
+    void setOverdrawViz(bool overdrawViz);
     bool getOverdrawViz() const { return fOverdrawViz; }
 
     bool getAllowSimplifyClip() const { return fAllowSimplifyClip; }
@@ -232,10 +232,10 @@ private:
     SkPath fSaveDevPath;
 
     bool fOverdrawViz;
-    SkDrawFilter* fOverdrawFilter;
+    bool fOverrideFilterQuality;
+    SkFilterQuality fFilterQuality;
 
-    bool fOverrideTexFiltering;
-    SkTexOverrideFilter* fTexOverrideFilter;
+    SkAutoTUnref<SkNWayCanvas> fPaintFilterCanvas;
 
     /**
         The active saveLayer commands at a given point in the renderering.
@@ -274,6 +274,8 @@ private:
     void outputPointsCommon(const SkPoint* pts, int count);
     void outputScalar(SkScalar num);
 
+    void updatePaintFilterCanvas();
+
     typedef SkCanvas INHERITED;
 };