Rewrite GrTextureMaker to disentangle bitmap case from base class and give GPU object a say in what…

src/gpu/GrTextureMaker.h

-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef GrTextureMaker_DEFINED
-#define GrTextureMaker_DEFINED
-
-#include "SkGrPriv.h"
-
-class GrContext;
-class GrTexture;
-class GrTextureParams;
-class GrUniqueKey;
-class SkBitmap;
-
-class GrTextureMaker {
-public:
-    GrTextureMaker(int width, int height) : fWidth(width), fHeight(height) {}
-    virtual ~GrTextureMaker() {}
-
-    int width() const { return fWidth; }
-    int height() const { return fHeight; }
-
-    GrTexture* refCachedTexture(GrContext*, const GrTextureParams&);
-
-protected:
-    /**
-     *  Return the maker's "original" unstretched texture. It is the responsibility of the maker
-     *  to make this efficient ... if the texture is being generated, the maker must handle
-     *  caching it.
-     */
-    virtual GrTexture* onRefUnstretchedTexture(GrContext*) = 0;
-
-    /**
-     *  If we need to stretch the maker's original texture, the maker is asked to return a key
-     *  that identifies its origianl + the stretch parameter. If the maker does not want to cache
-     *  the stretched version (e.g. the maker is volatile), this should ignore the key parameter
-     *  and return false.
-     */
-    virtual bool onMakeStretchedKey(const SkGrStretch&, GrUniqueKey* stretchedKey) = 0;
-
-    /**
-     *  Return a new (uncached) texture that is the stretch of the maker's original.
-     *
-     *  The base-class handles general logic for this, and only needs access to the following
-     *  methods:
-     *  - onRefUnstretchedTexture()
-     *  - onGetROBitmap()
-     *
-     *  Subclass may override this if they can handle stretching more efficiently.
-     */
-    virtual GrTexture* onGenerateStretchedTexture(GrContext*, const SkGrStretch&);
-
-    /**
-     *  If a stretched version of the texture is generated, it may be cached (assuming that
-     *  onMakeStretchedKey() returns true). In that case, the maker is notified in case it
-     *  wants to note that for when the maker is destroyed.
-     */
-    virtual void onNotifyStretchCached(const GrUniqueKey& stretchedKey) = 0;
-
-    /**
-     *  Some GPUs are unreliable w/ very small texture sizes. If we run into that case, this
-     *  method will be called (in service of onGenerateStretchedTexture) to return a raster version
-     *  of the original texture.
-     */
-    virtual bool onGetROBitmap(SkBitmap*) = 0;
-
-private:
-    const int fWidth;
-    const int fHeight;
-};
-
-#endif