Revert of Revert of Revert "De-virtualize SkCanvas save/restore."

src/utils/SkNoSaveLayerCanvas.h

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef SkNoSaveLayerCanvas_DEFINED
 #define SkNoSaveLayerCanvas_DEFINED
 
 #include "SkCanvas.h"
 #include "SkRRect.h"
 
 // The NoSaveLayerCanvas is used to play back SkPictures when the saveLayer
 // functionality isn't required (e.g., during analysis of the draw calls).
 // It also simplifies the clipping calls to only use rectangles.
 class SkNoSaveLayerCanvas : public SkCanvas {
 public:
     SkNoSaveLayerCanvas(SkBaseDevice* device) : INHERITED(device) {}
 
-protected:
-    virtual bool onSaveLayer(const SkRect* bounds, const SkPaint* paint, SaveFlags flags)
-        SK_OVERRIDE {
-        this->INHERITED::onSaveLayer(bounds, paint, flags);
-        return false;
+    // turn saveLayer() into save() for speed, should not affect correctness.
+    virtual int saveLayer(const SkRect* bounds,
+                          const SkPaint* paint,
+                          SaveFlags flags) SK_OVERRIDE {
+
+        // Like SkPictureRecord, we don't want to create layers, but we do need
+        // to respect the save and (possibly) its rect-clip.
+        int count = this->INHERITED::save(flags);
+        if (NULL != bounds) {
+            this->INHERITED::clipRectBounds(bounds, flags, NULL);
+        }
+        return count;
     }
 
+protected:
     // disable aa for speed
     virtual void onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
         this->INHERITED::onClipRect(rect, op, kHard_ClipEdgeStyle);
     }
 
     // for speed, just respect the bounds, and disable AA. May give us a few
     // false positives and negatives.
     virtual void onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
         this->updateClipConservativelyUsingBounds(path.getBounds(), op,
                                                   path.isInverseFillType());
     }
     virtual void onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle) SK_OVERRIDE {
         this->updateClipConservativelyUsingBounds(rrect.getBounds(), op, false);
     }
 
 private:
     typedef SkCanvas INHERITED;
 };
 
 #endif // SkNoSaveLayerCanvas_DEFINED