More framework support for TransferBuffers

src/gpu/GrResourceProvider.h

Index: src/gpu/GrResourceProvider.h
diff --git a/src/gpu/GrResourceProvider.h b/src/gpu/GrResourceProvider.h
index 6c5737191b8b81d5ee76807392528893c2b9908c..6f444e9e8d87c0035ef70d399fd21a9ec022b841 100644
--- a/src/gpu/GrResourceProvider.h
+++ b/src/gpu/GrResourceProvider.h
@@ -112,6 +112,13 @@ public:
     };
     GrIndexBuffer* createIndexBuffer(size_t size, BufferUsage, uint32_t flags);
     GrVertexBuffer* createVertexBuffer(size_t size, BufferUsage, uint32_t flags);
+    enum TransferType {

[bsalomon, 2015/12/18 15:24:38]

We could put this in GrTypesPriv.h if you anticipate having a bunch of redefs of
this basic idea.

[jvanverth1, 2016/01/04 21:24:09]

Done.

+        /** Caller intends to use the buffer to transfer data to the GPU */
+        kCpuToGpu_TransferType,
+        /** Caller intends to use the buffer to transfer data from the GPU */
+        kGpuToCpu_TransferType
+    };    
+    GrTransferBuffer* createTransferBuffer(size_t size, TransferType, uint32_t flags);
 
     GrTexture* createApproxTexture(const GrSurfaceDesc& desc, uint32_t flags) {
         SkASSERT(0 == flags || kNoPendingIO_Flag == flags);