Revert of Consolidate GPU buffer implementations

src/gpu/GrGpu.h

Index: src/gpu/GrGpu.h
diff --git a/src/gpu/GrGpu.h b/src/gpu/GrGpu.h
index a49b2c28fd9802c41749912c7bf84792f0ef0be5..4e9b247ca3dd9596e58f117c284ab0d694eb4c42 100644
--- a/src/gpu/GrGpu.h
+++ b/src/gpu/GrGpu.h
@@ -20,9 +20,9 @@
 #include "SkTArray.h"
 
 class GrBatchTracker;
-class GrBuffer;
 class GrContext;
 class GrGLContext;
+class GrIndexBuffer;
 class GrMesh;
 class GrNonInstancedVertices;
 class GrPath;
@@ -36,6 +36,8 @@
 class GrStencilAttachment;
 class GrSurface;
 class GrTexture;
+class GrTransferBuffer;
+class GrVertexBuffer;
 
 class GrGpu : public SkRefCnt {
 public:
@@ -127,11 +129,39 @@
     GrRenderTarget* wrapBackendTextureAsRenderTarget(const GrBackendTextureDesc&, GrWrapOwnership);
 
     /**
-     * Creates a buffer.
-     *
-     * @return the buffer if successful, otherwise nullptr.
-     */
-    GrBuffer* createBuffer(GrBufferType, size_t size, GrAccessPattern);
+     * Creates a vertex buffer.
+     *
+     * @param size    size in bytes of the vertex buffer
+     * @param dynamic hints whether the data will be frequently changed
+     *                by either GrVertexBuffer::map() or
+     *                GrVertexBuffer::updateData().
+     *
+     * @return    The vertex buffer if successful, otherwise nullptr.
+     */
+    GrVertexBuffer* createVertexBuffer(size_t size, bool dynamic);
+
+    /**
+     * Creates an index buffer.
+     *
+     * @param size    size in bytes of the index buffer
+     * @param dynamic hints whether the data will be frequently changed
+     *                by either GrIndexBuffer::map() or
+     *                GrIndexBuffer::updateData().
+     *
+     * @return The index buffer if successful, otherwise nullptr.
+     */
+    GrIndexBuffer* createIndexBuffer(size_t size, bool dynamic);
+
+    /**
+     * Creates a transfer buffer.
+     *
+     * @param size      size in bytes of the index buffer
+     * @param toGpu     true if used to transfer from the cpu to the gpu
+     *                  otherwise to be used to transfer from the gpu to the cpu
+     *
+     * @return The transfer buffer if successful, otherwise nullptr.
+     */
+    GrTransferBuffer* createTransferBuffer(size_t size, TransferType type);
     
     /**
      * Resolves MSAA.
@@ -268,22 +298,22 @@
                      size_t rowBytes);
 
     /**
-     * Updates the pixels in a rectangle of a surface using a buffer
-     *
-     * @param surface          The surface to write to.
-     * @param left             left edge of the rectangle to write (inclusive)
-     * @param top              top edge of the rectangle to write (inclusive)
-     * @param width            width of rectangle to write in pixels.
-     * @param height           height of rectangle to write in pixels.
-     * @param config           the pixel config of the source buffer
-     * @param transferBuffer   GrBuffer to read pixels from (type must be "kCpuToGpu")
-     * @param offset           offset from the start of the buffer
-     * @param rowBytes         number of bytes between consecutive rows. Zero
-     *                         means rows are tightly packed.
+     * Updates the pixels in a rectangle of a surface using a GrTransferBuffer
+     *
+     * @param surface       The surface to write to.
+     * @param left          left edge of the rectangle to write (inclusive)
+     * @param top           top edge of the rectangle to write (inclusive)
+     * @param width         width of rectangle to write in pixels.
+     * @param height        height of rectangle to write in pixels.
+     * @param config        the pixel config of the source buffer
+     * @param buffer        GrTransferBuffer to read pixels from
+     * @param offset        offset from the start of the buffer
+     * @param rowBytes      number of bytes between consecutive rows. Zero
+     *                      means rows are tightly packed.
      */
     bool transferPixels(GrSurface* surface,
                         int left, int top, int width, int height,
-                        GrPixelConfig config, GrBuffer* transferBuffer,
+                        GrPixelConfig config, GrTransferBuffer* buffer,
                         size_t offset, size_t rowBytes);
 
     /**
@@ -528,7 +558,9 @@
                                                       GrWrapOwnership) = 0;
     virtual GrRenderTarget* onWrapBackendTextureAsRenderTarget(const GrBackendTextureDesc&,
                                                                GrWrapOwnership) = 0;
-    virtual GrBuffer* onCreateBuffer(GrBufferType, size_t size, GrAccessPattern) = 0;
+    virtual GrVertexBuffer* onCreateVertexBuffer(size_t size, bool dynamic) = 0;
+    virtual GrIndexBuffer* onCreateIndexBuffer(size_t size, bool dynamic) = 0;
+    virtual GrTransferBuffer* onCreateTransferBuffer(size_t size, TransferType type) = 0;
 
     // overridden by backend-specific derived class to perform the clear.
     virtual void onClear(GrRenderTarget*, const SkIRect& rect, GrColor color) = 0;
@@ -570,7 +602,7 @@
     // overridden by backend-specific derived class to perform the surface write
     virtual bool onTransferPixels(GrSurface*,
                                   int left, int top, int width, int height,
-                                  GrPixelConfig config, GrBuffer* transferBuffer,
+                                  GrPixelConfig config, GrTransferBuffer* buffer,
                                   size_t offset, size_t rowBytes) = 0;
 
     // overridden by backend-specific derived class to perform the resolve