Revert of Add transfer buffer support.

src/gpu/GrTransferBuffer.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 GrTransferBuffer_DEFINED
-#define GrTransferBuffer_DEFINED
-
-#include "GrGpuResource.h"
-
-class GrTransferBuffer : public GrGpuResource {
-public:
-    /**
-    * Maps the buffer to be written by the CPU.
-    *
-    * The previous content of the buffer is invalidated. It is an error
-    * to transfer to or from the buffer while it is mapped. It is an error to 
-    * call map on an already mapped buffer. Must be matched by an unmap() call.
-    * Currently only one map at a time is supported (no nesting of map/unmap).
-    *
-    * Note that buffer mapping does not go through GrContext and therefore is
-    * not serialized with other operations.
-    *
-    * @return a pointer to the data or nullptr if the map fails.
-    */
-    void* map() { return (fMapPtr = this->onMap()); }
-
-    /**
-    * Unmaps the buffer.
-    *
-    * The pointer returned by the previous map call will no longer be valid.
-    */
-    void unmap() {
-        SkASSERT(fMapPtr);
-        this->onUnmap();
-        fMapPtr = nullptr;
-    }
-
-    /**
-    * Returns the same ptr that map() returned at time of map or nullptr if the
-    * is not mapped.
-    *
-    * @return ptr to mapped buffer data or nullptr if buffer is not mapped.
-    */
-    void* mapPtr() const { return fMapPtr; }
-
-    /**
-    Queries whether the buffer has been mapped.
-
-    @return true if the buffer is mapped, false otherwise.
-    */
-    bool isMapped() const { return SkToBool(fMapPtr); }
-
-protected:
-    GrTransferBuffer(GrGpu* gpu, size_t gpuMemorySize)
-        : INHERITED(gpu, kUncached_LifeCycle)
-        , fGpuMemorySize(gpuMemorySize) {
-    }
-
-private:
-    virtual size_t onGpuMemorySize() const { return fGpuMemorySize; }
-
-    virtual void* onMap() = 0;
-    virtual void  onUnmap() = 0;
-
-    void*    fMapPtr;
-    size_t   fGpuMemorySize;
-
-    typedef GrGpuResource INHERITED;
-};
-
-#endif