Revert of Consolidate GPU buffer implementations

src/gpu/gl/GrGLBufferImpl.h

+/*
+ * Copyright 2013 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrGLBufferImpl_DEFINED
+#define GrGLBufferImpl_DEFINED
+
+#include "SkTypes.h"
+#include "gl/GrGLTypes.h"
+
+class GrGLGpu;
+
+/**
+ * This class serves as the implementation of GrGL*Buffer classes. It was written to avoid code
+ * duplication in those classes.
+ */
+class GrGLBufferImpl : SkNoncopyable {
+public:
+    enum Usage {
+        kStaticDraw_Usage = 0,
+        kDynamicDraw_Usage,
+        kStreamDraw_Usage,
+        kStreamRead_Usage,
+
+        kLast_Usage = kStreamRead_Usage
+    };
+    static const int kUsageCount = kLast_Usage + 1;
+
+    struct Desc {
+        GrGLuint    fID;            // set to 0 to indicate buffer is CPU-backed and not a VBO.
+        size_t      fSizeInBytes;
+        Usage       fUsage;
+    };
+
+    GrGLBufferImpl(GrGLGpu*, const Desc&, GrGLenum bufferType);
+    ~GrGLBufferImpl() {
+        // either release or abandon should have been called by the owner of this object.
+        SkASSERT(0 == fDesc.fID);
+    }
+
+    void abandon();
+    void release(GrGLGpu* gpu);
+
+    GrGLuint bufferID() const { return fDesc.fID; }
+    size_t baseOffset() const { return reinterpret_cast<size_t>(fCPUData); }
+    GrGLenum bufferType() const { return fBufferType; }
+
+    void* map(GrGLGpu* gpu);
+    void unmap(GrGLGpu* gpu);
+    bool isMapped() const;
+    bool updateData(GrGLGpu* gpu, const void* src, size_t srcSizeInBytes);
+
+private:
+    void validate() const;
+
+    Desc         fDesc;
+    GrGLenum     fBufferType; // GL_ARRAY_BUFFER or GL_ELEMENT_ARRAY_BUFFER, e.g.
+    void*        fCPUData;
+    void*        fMapPtr;
+    size_t       fGLSizeInBytes;     // In certain cases we make the size of the GL buffer object
+                                     // smaller or larger than the size in fDesc.
+
+    typedef SkNoncopyable INHERITED;
+};
+
+#endif