Consolidate GPU buffer implementations

src/gpu/vk/GrVkGpu.h

Index: src/gpu/vk/GrVkGpu.h
diff --git a/src/gpu/vk/GrVkGpu.h b/src/gpu/vk/GrVkGpu.h
index c39973a4e786c2be20bcce10f98f5cb7a7083d4b..d1526a13ac080420a7956ea974fc86b6c5b2d122 100644
--- a/src/gpu/vk/GrVkGpu.h
+++ b/src/gpu/vk/GrVkGpu.h
@@ -147,9 +147,7 @@ private:
         return NULL;
     }
 
-    GrVertexBuffer* onCreateVertexBuffer(size_t size, bool dynamic) override;
-    GrIndexBuffer* onCreateIndexBuffer(size_t size, bool dynamic) override;
-    GrTransferBuffer* onCreateTransferBuffer(size_t size, TransferType type) override;
+    GrBuffer* onCreateBuffer(GrBufferType, size_t size, GrAccessPattern) override;
 
     void onClear(GrRenderTarget*, const SkIRect& rect, GrColor color) override;
 
@@ -172,7 +170,7 @@ private:
 
     bool onTransferPixels(GrSurface*,
                           int left, int top, int width, int height,
-                          GrPixelConfig config, GrTransferBuffer* buffer,
+                          GrPixelConfig config, GrBuffer* transferBuffer,
                           size_t offset, size_t rowBytes) override {
         SkDebugf("onTransferPixels not yet implemented for Vulkan\n");
         return false;