Revert of Consolidate GPU buffer implementations

src/gpu/batches/GrAtlasTextBatch.h

Index: src/gpu/batches/GrAtlasTextBatch.h
diff --git a/src/gpu/batches/GrAtlasTextBatch.h b/src/gpu/batches/GrAtlasTextBatch.h
index 01d799233e136b7446bb169b834142e77c4865a9..435fb59d4920279183e5651913047523a78bffa9 100644
--- a/src/gpu/batches/GrAtlasTextBatch.h
+++ b/src/gpu/batches/GrAtlasTextBatch.h
@@ -99,8 +99,8 @@
     void initBatchTracker(const GrXPOverridesForBatch& overrides) override;
 
     struct FlushInfo {
-        SkAutoTUnref<const GrBuffer> fVertexBuffer;
-        SkAutoTUnref<const GrBuffer> fIndexBuffer;
+        SkAutoTUnref<const GrVertexBuffer> fVertexBuffer;
+        SkAutoTUnref<const GrIndexBuffer> fIndexBuffer;
         int fGlyphsToFlush;
         int fVertexOffset;
     };