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

src/core/SkRecordDraw.cpp

Index: src/core/SkRecordDraw.cpp
diff --git a/src/core/SkRecordDraw.cpp b/src/core/SkRecordDraw.cpp
index d0e8c4cf48b8354e56e4f0f0c92a214d96c11821..c3739705174ff0a6ae6eb8bd5dba8ca79d58b3d1 100644
--- a/src/core/SkRecordDraw.cpp
+++ b/src/core/SkRecordDraw.cpp
@@ -87,6 +87,8 @@ 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(TranslateZ, SkCanvas::translateZ(r.z));
+
 DRAW(DrawBitmap, drawBitmap(r.bitmap.shallowCopy(), r.left, r.top, r.paint));
 DRAW(DrawBitmapNine, drawBitmapNine(r.bitmap.shallowCopy(), r.center, r.dst, r.paint));
 DRAW(DrawBitmapRect,
@@ -287,6 +289,8 @@ private:
     void trackBounds(const ClipPath&)          { this->pushControl(); }
     void trackBounds(const ClipRegion&)        { this->pushControl(); }
 
+    void trackBounds(const TranslateZ&)              { this->pushControl(); }
+
     // For all other ops, we can calculate and store the bounds directly now.
     template <typename T> void trackBounds(const T& op) {
         fBounds[fCurrentOp] = this->bounds(op);