change 'n' toggle to cycle through all filterlevels

samplecode/SampleApp.h

 /*
  * Copyright 2011 Skia
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SampleApp_DEFINED
 #define SampleApp_DEFINED
 
@@ skipping 194 matching lines @@
     // The following are for the 'fatbits' drawing
     // Latest position of the mouse.
     int fMouseX, fMouseY;
     int fFatBitsScale;
     // Used by the text showing position and color values.
     SkTypeface* fTypeface;
     bool fShowZoomer;
 
     SkOSMenu::TriState fLCDState;
     SkOSMenu::TriState fAAState;
-    SkOSMenu::TriState fFilterState;
     SkOSMenu::TriState fSubpixelState;
     int fHintingState;
+    int fFilterLevelIndex;
     unsigned   fFlipAxis;
 
     int fMSAASampleCount;
 
     int fScrollTestX, fScrollTestY;
     SkScalar fZoomCenterX, fZoomCenterY;
 
     //Stores global settings
     SkOSMenu* fAppMenu; // We pass ownership to SkWindow, when we call addMenu
     //Stores slide specific settings
@@ skipping 13 matching lines @@
     void updateMatrix();
     void postAnimatingEvent();
     void installDrawFilter(SkCanvas*);
     int findByTitle(const char*);
     void listTitles();
 
     typedef SkOSWindow INHERITED;
 };
 
 #endif