Begin weaning GrClipMaskManager off of GrDrawTarget (take 2)

src/gpu/GrDrawContextPriv.h

+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrDrawContextPriv_DEFINED
+#define GrDrawContextPriv_DEFINED
+
+#include "GrDrawContext.h"
+
+class GrStencilSettings;
+
+/** Class that adds methods to GrDrawContext that are only intended for use internal to Skia.
+    This class is purely a privileged window into GrDrawContext. It should never have additional
+    data members or virtual methods. */
+class GrDrawContextPriv {
+public:
+    bool drawAndStencilRect(const SkIRect* scissorRect,
+                            const GrStencilSettings&,
+                            SkRegion::Op op,
+                            bool invert,
+                            bool doAA,
+                            const SkMatrix& viewMatrix,
+                            const SkRect&);
+
+    bool drawAndStencilPath(const SkIRect* scissorRect,
+                            const GrStencilSettings&,
+                            SkRegion::Op op,
+                            bool invert,
+                            bool doAA,
+                            const SkMatrix& viewMatrix,
+                            const SkPath&);
+
+    void testingOnly_drawBatch(const GrPipelineBuilder& pipelineBuilder,
+                               GrDrawBatch* batch);
+
+private:
+    explicit GrDrawContextPriv(GrDrawContext* drawContext) : fDrawContext(drawContext) {}
+    GrDrawContextPriv(const GrRenderTargetPriv&) {} // unimpl
+    GrDrawContextPriv& operator=(const GrRenderTargetPriv&); // unimpl
+
+    // No taking addresses of this type.
+    const GrDrawContextPriv* operator&() const;
+    GrDrawContextPriv* operator&();
+
+    GrDrawContext* fDrawContext;
+        
+    friend class GrDrawContext; // to construct/copy this type.
+};
+
+inline GrDrawContextPriv GrDrawContext::drawContextPriv() { return GrDrawContextPriv(this); }
+
+inline const GrDrawContextPriv GrDrawContext::drawContextPriv () const {
+    return GrDrawContextPriv(const_cast<GrDrawContext*>(this));
+}
+
+#endif
+