diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/GrStencilBuffer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/gpu/GrStencilBuffer.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,47 @@
+
+/*
+ * 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 "GrContext.h"
+#include "GrGpu.h"
+#include "GrResourceCache.h"
+
+void GrStencilBuffer::transferToCache() {
+    SkASSERT(NULL == this->getCacheEntry());
+
+    this->getGpu()->getContext()->addStencilBuffer(this);
+}
+
+namespace {
+// we should never have more than one stencil buffer with same combo of (width,height,samplecount)
+void gen_cache_id(int width, int height, int sampleCnt, GrCacheID* cacheID) {
+    static const GrCacheID::Domain gStencilBufferDomain = GrCacheID::GenerateDomain();
+    GrCacheID::Key key;
+    uint32_t* keyData = key.fData32;
+    keyData[0] = width;
+    keyData[1] = height;
+    keyData[2] = sampleCnt;
+    memset(keyData + 3, 0, sizeof(key) - 3 * sizeof(uint32_t));
+    GR_STATIC_ASSERT(sizeof(key) >= 3 * sizeof(uint32_t));
+    cacheID->reset(gStencilBufferDomain, key);
+}
+}
+
+GrResourceKey GrStencilBuffer::ComputeKey(int width,
+                                          int height,
+                                          int sampleCnt) {
+    // All SBs are created internally to attach to RTs so they all use the same domain.
+    static const GrResourceKey::ResourceType gStencilBufferResourceType =
+        GrResourceKey::GenerateResourceType();
+    GrCacheID id;
+    gen_cache_id(width, height, sampleCnt, &id);
+
+    // we don't use any flags for SBs currently.
+    return GrResourceKey(id, gStencilBufferResourceType, 0);
+}