Consolidate GPU buffer implementations

src/gpu/gl/GrGLBuffer.h

Index: src/gpu/gl/GrGLBuffer.h
diff --git a/src/gpu/gl/GrGLBuffer.h b/src/gpu/gl/GrGLBuffer.h
new file mode 100644
index 0000000000000000000000000000000000000000..90d2c43dfac2c969af240905c16bb48ed0162c44
--- /dev/null
+++ b/src/gpu/gl/GrGLBuffer.h
@@ -0,0 +1,61 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrGLBuffer_DEFINED
+#define GrGLBuffer_DEFINED
+
+#include "GrBuffer.h"
+#include "gl/GrGLTypes.h"
+
+class GrGLGpu;
+class GrGLCaps;
+
+class GrGLBuffer : public GrBuffer {
+public:
+    static GrGLBuffer* Create(GrGLGpu*, GrBufferType, size_t size, GrAccessPattern);
+
+    ~GrGLBuffer() {
+        // either release or abandon should have been called by the owner of this object.
+        SkASSERT(0 == fBufferID);
+    }
+
+    GrGLenum target() const { return fTarget; }
+    GrGLuint bufferID() const { return fBufferID; }
+    size_t baseOffset() const { return reinterpret_cast<size_t>(fCPUData); }
+
+protected:
+    GrGLBuffer(GrGLGpu*, GrBufferType, size_t size, GrAccessPattern, bool cpuBacked);
+
+    void onAbandon() override;
+    void onRelease() override;
+    void setMemoryBacking(SkTraceMemoryDump* traceMemoryDump,
+                          const SkString& dumpName) const override;
+
+private:
+    GrGLGpu* glGpu() const;
+    const GrGLCaps& glCaps() const;
+
+    void onMap() override;
+    void onUnmap() override;
+    bool onUpdateData(const void* src, size_t srcSizeInBytes) override;
+
+#ifdef SK_DEBUG
+    void validate() const;
+#endif
+
+    void*        fCPUData;
+    GrGLenum     fTarget; // GL_ARRAY_BUFFER or GL_ELEMENT_ARRAY_BUFFER, e.g.
+    GrGLuint     fBufferID;
+    size_t       fSizeInBytes;
+    GrGLenum     fUsage;
+    size_t       fGLSizeInBytes;     // In certain cases we make the size of the GL buffer object
+                                     // smaller or larger than the size in fDesc.
+
+    typedef GrBuffer INHERITED;
+};
+
+#endif