Use scratch keys for stencil buffers.

include/gpu/GrContext.h

Index: include/gpu/GrContext.h
diff --git a/include/gpu/GrContext.h b/include/gpu/GrContext.h
index b83df457431ca0cfb57bfdf8d2130be7c3f91e0f..c6dd2d75631af38fdef00e2a933c144e11b90680 100644
--- a/include/gpu/GrContext.h
+++ b/include/gpu/GrContext.h
@@ -34,7 +34,6 @@ class GrPath;
 class GrPathRenderer;
 class GrResourceEntry;
 class GrResourceCache2;
-class GrStencilBuffer;
 class GrTestTarget;
 class GrTextContext;
 class GrTextureParams;
@@ -890,13 +889,6 @@ public:
     void addGpuTraceMarker(const GrGpuTraceMarker* marker);
     void removeGpuTraceMarker(const GrGpuTraceMarker* marker);
 
-    /**
-     * Stencil buffers add themselves to the cache using addStencilBuffer. findStencilBuffer is
-     * called to check the cache for a SB that matches an RT's criteria.
-     */
-    void addStencilBuffer(GrStencilBuffer* sb);
-    GrStencilBuffer* findAndRefStencilBuffer(int width, int height, int sampleCnt);
-
     GrPathRenderer* getPathRenderer(
                     const GrDrawTarget* target,
                     const GrDrawState*,