Revert of Consolidate GPU buffer implementations

src/gpu/GrBatchFlushState.h

Index: src/gpu/GrBatchFlushState.h
diff --git a/src/gpu/GrBatchFlushState.h b/src/gpu/GrBatchFlushState.h
index be9d790597671b242b3aba2f5df94f883bbc9575..1f82453c2e5ea3ba527328202660c7cfc825adeb 100644
--- a/src/gpu/GrBatchFlushState.h
+++ b/src/gpu/GrBatchFlushState.h
@@ -76,8 +76,8 @@
     GrBatchToken asapToken() const { return fLastFlushedToken + 1; }
 
     void* makeVertexSpace(size_t vertexSize, int vertexCount,
-                          const GrBuffer** buffer, int* startVertex);
-    uint16_t* makeIndexSpace(int indexCount, const GrBuffer** buffer, int* startIndex);
+                          const GrVertexBuffer** buffer, int* startVertex);
+    uint16_t* makeIndexSpace(int indexCount, const GrIndexBuffer** buffer, int* startIndex);
 
     /** This is called after each batch has a chance to prepare its draws and before the draws
         are issued. */
@@ -172,11 +172,11 @@
     }
 
     void* makeVertexSpace(size_t vertexSize, int vertexCount,
-                          const GrBuffer** buffer, int* startVertex) {
+                          const GrVertexBuffer** buffer, int* startVertex) {
         return this->state()->makeVertexSpace(vertexSize, vertexCount, buffer, startVertex);
     }
 
-    uint16_t* makeIndexSpace(int indexCount, const GrBuffer** buffer, int* startIndex) {
+    uint16_t* makeIndexSpace(int indexCount, const GrIndexBuffer** buffer, int* startIndex) {
         return this->state()->makeIndexSpace(indexCount, buffer, startIndex);
     }