Consolidate GPU buffer implementations

src/gpu/gl/GrGLTransferBuffer.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 GrGLTransferBuffer_DEFINED
-#define GrGLTransferBuffer_DEFINED
-
-#include "GrTransferBuffer.h"
-#include "GrGLBufferImpl.h"
-#include "gl/GrGLInterface.h"
-
-class GrGLGpu;
-
-class GrGLTransferBuffer : public GrTransferBuffer {
-
-public:
-    typedef GrGLBufferImpl::Desc Desc;
-
-    GrGLTransferBuffer(GrGLGpu* gpu, const Desc& desc, GrGLenum type);
-
-    GrGLuint bufferID() const { return fImpl.bufferID(); }
-    size_t baseOffset() const { return fImpl.baseOffset(); }
-    GrGLenum bufferType() const { return fImpl.bufferType(); }
-
-protected:
-    void onAbandon() override;
-    void onRelease() override;
-    void setMemoryBacking(SkTraceMemoryDump* traceMemoryDump,
-                          const SkString& dumpName) const override;
-
-private:
-    void* onMap() override;
-    void onUnmap() override;
-
-    GrGLGpu* getGpuGL() const {
-        SkASSERT(!this->wasDestroyed());
-        return (GrGLGpu*)(this->getGpu());
-    }
-
-    GrGLBufferImpl fImpl;
-
-    typedef GrTransferBuffer INHERITED;
-};
-
-#endif