Add a release procedure to SkMallocPixelRef; remove SkDataPixelRef

src/image/SkDataPixelRef.h

-/*
- * Copyright 2012 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkDataPixelRef_DEFINED
-#define SkDataPixelRef_DEFINED
-
-#include "SkPixelRef.h"
-
-class SkData;
-
-class SkDataPixelRef : public SkPixelRef {
-public:
-            SkDataPixelRef(const SkImageInfo&, SkData* data);
-    virtual ~SkDataPixelRef();
-
-    SK_DECLARE_PUBLIC_FLATTENABLE_DESERIALIZATION_PROCS(SkDataPixelRef)
-
-protected:
-    virtual void* onLockPixels(SkColorTable**) SK_OVERRIDE;
-    virtual void onUnlockPixels() SK_OVERRIDE;
-    virtual size_t getAllocatedSizeInBytes() const SK_OVERRIDE;
-
-    SkDataPixelRef(SkFlattenableReadBuffer& buffer);
-    virtual void flatten(SkFlattenableWriteBuffer&) const SK_OVERRIDE;
-
-private:
-    SkData* fData;
-
-    typedef SkPixelRef INHERITED;
-};
-
-#endif