Consolidate GPU buffer implementations

src/gpu/vk/GrVkGpu.cpp

Index: src/gpu/vk/GrVkGpu.cpp
diff --git a/src/gpu/vk/GrVkGpu.cpp b/src/gpu/vk/GrVkGpu.cpp
index 96c74ddd5dc1df2217723b50877adb93baec072d..068765db6b86ac1cba7bafffdcf0ba0060a1d620 100644
--- a/src/gpu/vk/GrVkGpu.cpp
+++ b/src/gpu/vk/GrVkGpu.cpp
@@ -389,18 +389,19 @@ void GrVkGpu::submitCommandBuffer(SyncQueue sync) {
 }
 
 ///////////////////////////////////////////////////////////////////////////////
-GrVertexBuffer* GrVkGpu::onCreateVertexBuffer(size_t size, bool dynamic) {
-    return GrVkVertexBuffer::Create(this, size, dynamic);
-}
-
-GrIndexBuffer* GrVkGpu::onCreateIndexBuffer(size_t size, bool dynamic) {
-    return GrVkIndexBuffer::Create(this, size, dynamic);
-}
-
-GrTransferBuffer* GrVkGpu::onCreateTransferBuffer(size_t size, TransferType type) {
-    GrVkBuffer::Type bufferType = kCpuToGpu_TransferType ? GrVkBuffer::kCopyRead_Type 
-                                                         : GrVkBuffer::kCopyWrite_Type;
-    return GrVkTransferBuffer::Create(this, size, bufferType);
+GrBuffer* GrVkGpu::onCreateBuffer(GrBufferType type, size_t size, GrAccessPattern accessPattern) {
+    switch (type) {
+        case kVertex_GrBufferType:
+            return GrVkVertexBuffer::Create(this, size, accessPattern);
+        case kIndex_GrBufferType:
+            return GrVkIndexBuffer::Create(this, size, accessPattern);
+        case kXferCpuToGpu_GrBufferType:
+        case kXferGpuToCpu_GrBufferType:
+            return GrVkTransferBuffer::Create(this, size, type);
+        default:
+            SkFAIL("Unknown buffer type.");
+            return nullptr;
+    }
 }
 
 ////////////////////////////////////////////////////////////////////////////////
@@ -556,7 +557,7 @@ bool GrVkGpu::uploadTexData(GrVkTexture* tex,
         GR_VK_CALL(interface, UnmapMemory(fDevice, tex->textureMemory()));
     } else {
         GrVkTransferBuffer* transferBuffer =
-            GrVkTransferBuffer::Create(this, trimRowBytes * height, GrVkBuffer::kCopyRead_Type);
+            GrVkTransferBuffer::Create(this, trimRowBytes * height, kXferCpuToGpu_GrBufferType);
 
         void* mapPtr = transferBuffer->map();
 
@@ -1441,8 +1442,7 @@ bool GrVkGpu::onReadPixels(GrSurface* surface,
                         false);
 
     GrVkTransferBuffer* transferBuffer = 
-        reinterpret_cast<GrVkTransferBuffer*>(this->createTransferBuffer(rowBytes * height, 
-                                                                         kGpuToCpu_TransferType));
+        GrVkTransferBuffer::Create(this, rowBytes * height, kXferGpuToCpu_GrBufferType);
 
     bool flipY = kBottomLeft_GrSurfaceOrigin == surface->origin();
     VkOffset3D offset = {