Rename GrStencilBuffer to GrStencilAttachment

src/gpu/GrStencilBuffer.cpp

-
-/*
- * Copyright 2011 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "GrStencilBuffer.h"
-#include "GrResourceKey.h"
-
-void GrStencilBuffer::ComputeSharedStencilBufferKey(int width, int height, int sampleCnt,
-                                                    GrUniqueKey* key) {
-    static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
-    GrUniqueKey::Builder builder(key, kDomain, 3);
-    builder[0] = width;
-    builder[1] = height;
-    builder[2] = sampleCnt;
-}