Suggested version with 'undo'.

dm/DMSrcSink.h

 #ifndef DMSrcSink_DEFINED
 #define DMSrcSink_DEFINED
 
 #include "DMGpuSupport.h"
 #include "SkBBHFactory.h"
 #include "SkBBoxHierarchy.h"
 #include "SkBitmap.h"
 #include "SkCanvas.h"
 #include "SkData.h"
 #include "SkGPipe.h"
@@ skipping 145 matching lines @@
     ViaMatrix(SkMatrix, Sink*);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return fSink->enclave(); }
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     SkMatrix            fMatrix;
     SkAutoTDelete<Sink> fSink;
 };
 
+class ViaUpright : public Sink {
+public:
+    ViaUpright(SkMatrix, Sink*);
+
+    Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
+    int enclave() const SK_OVERRIDE { return fSink->enclave(); }
+    const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
+private:
+    SkMatrix            fMatrix;
+    SkAutoTDelete<Sink> fSink;
+};
+
 class ViaPipe : public Sink {
 public:
     explicit ViaPipe(Sink*);
 
     Error draw(const Src&, SkBitmap*, SkWStream*, SkString*) const SK_OVERRIDE;
     int enclave() const SK_OVERRIDE { return fSink->enclave(); }
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     SkAutoTDelete<Sink>  fSink;
 };
@@ skipping 18 matching lines @@
     const char* fileExtension() const SK_OVERRIDE { return fSink->fileExtension(); }
 private:
     const int                   fW, fH;
     SkAutoTDelete<SkBBHFactory> fFactory;
     SkAutoTDelete<Sink>         fSink;
 };
 
 }  // namespace DM
 
 #endif//DMSrcSink_DEFINED