move GrPixelRef headers to private (as we work to eliminate them)

include/gpu/SkGrPixelRef.h

-/*
- * Copyright 2010 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkGrPixelRef_DEFINED
-#define SkGrPixelRef_DEFINED
-
-#include "SkBitmap.h"
-#include "SkPixelRef.h"
-#include "GrTexture.h"
-#include "GrRenderTarget.h"
-
-
-/**
- *  Common baseclass that implements onLockPixels() by calling onReadPixels().
- *  Since it has a copy, it always returns false for onLockPixelsAreWritable().
- */
-class SK_API SkROLockPixelsPixelRef : public SkPixelRef {
-public:
-    SkROLockPixelsPixelRef(const SkImageInfo&);
-    virtual ~SkROLockPixelsPixelRef();
-
-protected:
-    bool onNewLockPixels(LockRec*) override;
-    void onUnlockPixels() override;
-    bool onLockPixelsAreWritable() const override;   // return false;
-
-private:
-    SkBitmap    fBitmap;
-    typedef SkPixelRef INHERITED;
-};
-
-/**
- *  PixelRef that wraps a GrSurface
- */
-class SK_API SkGrPixelRef : public SkROLockPixelsPixelRef {
-public:
-    /**
-     * Constructs a pixel ref around a GrSurface.
-     */
-    SkGrPixelRef(const SkImageInfo&, GrSurface*);
-    virtual ~SkGrPixelRef();
-
-    // override from SkPixelRef
-    GrTexture* getTexture() override;
-
-protected:
-    // overrides from SkPixelRef
-    bool onReadPixels(SkBitmap* dst, SkColorType, const SkIRect* subset) override;
-    SkPixelRef* deepCopy(SkColorType, SkColorSpace*, const SkIRect* subset) override;
-    void onNotifyPixelsChanged() override;
-
-private:
-    GrSurface*  fSurface;
-    typedef SkROLockPixelsPixelRef INHERITED;
-};
-
-#endif