Revert of De-virtualize SkCanvas save/restore.

experimental/PdfViewer/SkNulCanvas.h

Index: experimental/PdfViewer/SkNulCanvas.h
diff --git a/experimental/PdfViewer/SkNulCanvas.h b/experimental/PdfViewer/SkNulCanvas.h
index 7c1c1cabd934f86f7b5670a65e9d39f422033960..1c12a5b88faba60d52a1961152cef9cd9e47d0a8 100644
--- a/experimental/PdfViewer/SkNulCanvas.h
+++ b/experimental/PdfViewer/SkNulCanvas.h
@@ -26,6 +26,13 @@
     explicit SkNulCanvas(const SkBitmap& bitmap) : SkCanvas(bitmap) {}
     virtual ~SkNulCanvas() {}
 
+    virtual int save(SaveFlags flags = kMatrixClip_SaveFlag) SK_OVERRIDE {return 0;}
+    virtual int saveLayer(const SkRect* bounds, const SkPaint* paint,
+                          SaveFlags flags = kARGB_ClipLayer_SaveFlag) SK_OVERRIDE {return 0;}
+    int saveLayerAlpha(const SkRect* bounds, U8CPU alpha,
+                       SaveFlags flags = kARGB_ClipLayer_SaveFlag) {return 0;}
+    virtual void restore() SK_OVERRIDE {}
+    int getSaveCount() const {return 0;}
     virtual bool isDrawingToLayer() const SK_OVERRIDE {return false;}
     virtual bool translate(SkScalar dx, SkScalar dy) SK_OVERRIDE {return true;}
     virtual bool scale(SkScalar sx, SkScalar sy) SK_OVERRIDE {return true;}
@@ -99,12 +106,6 @@
     virtual SkCanvas* canvasForDrawIter() {return NULL;}
     virtual SkBaseDevice* setDevice(SkBaseDevice* device) {return NULL;}
 
-    virtual bool onSaveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags)
-        SK_OVERRIDE {
-        this->INHERITED::onSaveLayer(bounds, paint, flags);
-        return false;
-    }
-
     virtual void onClipRect(const SkRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE {}
     virtual void onClipRRect(const SkRRect&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE {}
     virtual void onClipPath(const SkPath&, SkRegion::Op, ClipEdgeStyle) SK_OVERRIDE {}