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

src/core/SkRecorder.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 SkRecorder_DEFINED
 #define SkRecorder_DEFINED
 
@@ skipping 42 matching lines @@
     // Make SkRecorder forget entirely about its SkRecord*; all calls to SkRecorder will fail.
     void forgetRecord();
 
     void willSave() override;
     SaveLayerStrategy getSaveLayerStrategy(const SaveLayerRec&) override;
     void willRestore() override {}
     void didRestore() override;
 
     void didConcat(const SkMatrix&) override;
     void didSetMatrix(const SkMatrix&) override;
+    void didTranslateZ(SkScalar) override;
 
     void onDrawDRRect(const SkRRect&, const SkRRect&, const SkPaint&) override;
     void onDrawDrawable(SkDrawable*, const SkMatrix*) override;
     void onDrawText(const void* text,
                     size_t byteLength,
                     SkScalar x,
                     SkScalar y,
                     const SkPaint& paint) override;
     void onDrawPosText(const void* text,
                        size_t byteLength,
@@ skipping 68 matching lines @@
 
     DrawPictureMode fDrawPictureMode;
     size_t fApproxBytesUsedBySubPictures;
     SkRecord* fRecord;
     SkAutoTDelete<SkDrawableList> fDrawableList;
 
     SkMiniRecorder* fMiniRecorder;
 };
 
 #endif//SkRecorder_DEFINED