Added the framework for having canvas/recorder/picture record depth_set's.

src/core/SkRecorder.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 "SkBigPicture.h"
 #include "SkCanvasPriv.h"
 #include "SkPatchUtils.h"
@@ skipping 341 matching lines @@
 }
 
 void SkRecorder::didConcat(const SkMatrix& matrix) {
     APPEND(Concat, matrix);
 }
 
 void SkRecorder::didSetMatrix(const SkMatrix& matrix) {
     APPEND(SetMatrix, matrix);
 }
 
+void SkRecorder::didTranslateZ(SkScalar z)  {
+    APPEND(TranslateZ, z);
+}
+
 void SkRecorder::onClipRect(const SkRect& rect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
     INHERITED(onClipRect, rect, op, edgeStyle);
     SkRecords::RegionOpAndAA opAA(op, kSoft_ClipEdgeStyle == edgeStyle);
     APPEND(ClipRect, this->devBounds(), rect, opAA);
 }
 
 void SkRecorder::onClipRRect(const SkRRect& rrect, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
     INHERITED(onClipRRect, rrect, op, edgeStyle);
     SkRecords::RegionOpAndAA opAA(op, kSoft_ClipEdgeStyle == edgeStyle);
     APPEND(ClipRRect, this->devBounds(), rrect, opAA);
 }
 
 void SkRecorder::onClipPath(const SkPath& path, SkRegion::Op op, ClipEdgeStyle edgeStyle) {
     INHERITED(onClipPath, path, op, edgeStyle);
     SkRecords::RegionOpAndAA opAA(op, kSoft_ClipEdgeStyle == edgeStyle);
     APPEND(ClipPath, this->devBounds(), path, opAA);
 }
 
 void SkRecorder::onClipRegion(const SkRegion& deviceRgn, SkRegion::Op op) {
     INHERITED(onClipRegion, deviceRgn, op);
     APPEND(ClipRegion, this->devBounds(), deviceRgn, op);
 }
 
 sk_sp<SkSurface> SkRecorder::onNewSurface(const SkImageInfo&, const SkSurfaceProps&) {
     return nullptr;
 }