Alter SkCanvas::drawPicture (devirtualize, take const SkPicture, take pointer)

experimental/PdfViewer/SkNulCanvas.h

Index: experimental/PdfViewer/SkNulCanvas.h
diff --git a/experimental/PdfViewer/SkNulCanvas.h b/experimental/PdfViewer/SkNulCanvas.h
index 1790b4870402557142f8b036217e1a9be135452b..a976ea49da8d192e079dac0e756730613aee7297 100644
--- a/experimental/PdfViewer/SkNulCanvas.h
+++ b/experimental/PdfViewer/SkNulCanvas.h
@@ -47,7 +47,6 @@ public:
                                 const SkRect& dst, const SkPaint* paint = NULL) SK_OVERRIDE {}
     virtual void drawSprite(const SkBitmap& bitmap, int left, int top,
                             const SkPaint* paint = NULL) SK_OVERRIDE {}
-    virtual void drawPicture(SkPicture& picture) SK_OVERRIDE {}
     virtual void drawVertices(VertexMode vmode, int vertexCount,
                               const SkPoint vertices[], const SkPoint texs[],
                               const SkColor colors[], SkXfermode* xmode,
@@ -104,6 +103,8 @@ protected:
     virtual void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE {}
     virtual void onClipRegion(const SkRegion&, SkRegion::Op)  SK_OVERRIDE {}
 
+    virtual void onDrawPicture(const SkPicture* picture) SK_OVERRIDE {}
+    
 private:
     typedef SkCanvas INHERITED;
 };