add backdrop option to SaveLayerRec

src/core/SkRecordDraw.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkLayerInfo.h"
 #include "SkRecordDraw.h"
 #include "SkPatchUtils.h"
@@ skipping 60 matching lines @@
 }
 
 namespace SkRecords {
 
 // NoOps draw nothing.
 template <> void Draw::draw(const NoOp&) {}
 
 #define DRAW(T, call) template <> void Draw::draw(const T& r) { fCanvas->call; }
 DRAW(Restore, restore());
 DRAW(Save, save());
-DRAW(SaveLayer, saveLayer(SkCanvas::SaveLayerRec(r.bounds, r.paint, r.saveLayerFlags)));
+DRAW(SaveLayer, saveLayer(SkCanvas::SaveLayerRec(r.bounds, r.paint, r.backdrop, r.saveLayerFlags)));
 DRAW(SetMatrix, setMatrix(SkMatrix::Concat(fInitialCTM, r.matrix)));
 DRAW(Concat, concat(r.matrix));
 
 DRAW(ClipPath, clipPath(r.path, r.opAA.op, r.opAA.aa));
 DRAW(ClipRRect, clipRRect(r.rrect, r.opAA.op, r.opAA.aa));
 DRAW(ClipRect, clipRect(r.rect, r.opAA.op, r.opAA.aa));
 DRAW(ClipRegion, clipRegion(r.region, r.op));
 
 DRAW(DrawBitmap, drawBitmap(r.bitmap.shallowCopy(), r.left, r.top, r.paint));
 DRAW(DrawBitmapNine, drawBitmapNine(r.bitmap.shallowCopy(), r.center, r.dst, r.paint));
@@ skipping 708 matching lines @@
 void SkRecordComputeLayers(const SkRect& cullRect, const SkRecord& record, SkRect bounds[],
                            const SkBigPicture::SnapshotArray* pictList, SkLayerInfo* data) {
     SkRecords::CollectLayers visitor(cullRect, record, bounds, pictList, data);
     for (int curOp = 0; curOp < record.count(); curOp++) {
         visitor.setCurrentOp(curOp);
         record.visit<void>(curOp, visitor);
     }
     visitor.cleanUp();
 }