install drawfilter for the picture playback as well



git-svn-id: http://skia.googlecode.com/svn/trunk@2839 2bbb7eff-a529-9590-31e7-b0007b416f81
diff --git a/samplecode/SampleApp.h b/samplecode/SampleApp.h
index 0a60535..cd07206 100644
--- a/samplecode/SampleApp.h
+++ b/samplecode/SampleApp.h
@@ -189,6 +189,7 @@
     void showZoomer(SkCanvas* canvas);
     void updateMatrix();
     void postAnimatingEvent();
+    void installDrawFilter(SkCanvas*);
 
     typedef SkOSWindow INHERITED;
 };