diff -r 000000000000 -r 6474c204b198 gfx/skia/trunk/src/gpu/GrStencilBuffer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gfx/skia/trunk/src/gpu/GrStencilBuffer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,81 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#ifndef GrStencilBuffer_DEFINED
+#define GrStencilBuffer_DEFINED
+
+#include "GrClipData.h"
+#include "GrResource.h"
+
+class GrRenderTarget;
+class GrResourceEntry;
+class GrResourceKey;
+
+class GrStencilBuffer : public GrResource {
+public:
+    SK_DECLARE_INST_COUNT(GrStencilBuffer);
+
+    virtual ~GrStencilBuffer() {
+        // TODO: allow SB to be purged and detach itself from rts
+    }
+
+    int width() const { return fWidth; }
+    int height() const { return fHeight; }
+    int bits() const { return fBits; }
+    int numSamples() const { return fSampleCnt; }
+
+    // called to note the last clip drawn to this buffer.
+    void setLastClip(int32_t clipStackGenID,
+                     const SkIRect& clipSpaceRect,
+                     const SkIPoint clipSpaceToStencilOffset) {
+        fLastClipStackGenID = clipStackGenID;
+        fLastClipStackRect = clipSpaceRect;
+        fLastClipSpaceOffset = clipSpaceToStencilOffset;
+    }
+
+    // called to determine if we have to render the clip into SB.
+    bool mustRenderClip(int32_t clipStackGenID,
+                        const SkIRect& clipSpaceRect,
+                        const SkIPoint clipSpaceToStencilOffset) const {
+        return fLastClipStackGenID != clipStackGenID ||
+               fLastClipSpaceOffset != clipSpaceToStencilOffset ||
+               !fLastClipStackRect.contains(clipSpaceRect);
+    }
+
+    // Places the sb in the cache. The cache takes a ref of the stencil buffer.
+    void transferToCache();
+
+    static GrResourceKey ComputeKey(int width, int height, int sampleCnt);
+
+protected:
+    GrStencilBuffer(GrGpu* gpu, bool isWrapped, int width, int height, int bits, int sampleCnt)
+        : GrResource(gpu, isWrapped)
+        , fWidth(width)
+        , fHeight(height)
+        , fBits(bits)
+        , fSampleCnt(sampleCnt)
+        , fLastClipStackGenID(SkClipStack::kInvalidGenID) {
+        fLastClipStackRect.setEmpty();
+    }
+
+private:
+
+    int fWidth;
+    int fHeight;
+    int fBits;
+    int fSampleCnt;
+
+    int32_t     fLastClipStackGenID;
+    SkIRect     fLastClipStackRect;
+    SkIPoint    fLastClipSpaceOffset;
+
+    typedef GrResource INHERITED;
+};
+
+#endif