Fix memory leak

src/gpu/GrPathRenderingDrawContext.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 GrPathRenderingDrawContext_DEFINED
 #define GrPathRenderingDrawContext_DEFINED
 
@@ skipping 11 matching lines @@
                      const SkScalar pos[], int scalarsPerPosition,
                      const SkPoint& offset, const SkIRect& clipBounds) override;
     void drawTextBlob(const GrClip&, const SkPaint&,
                       const SkMatrix& viewMatrix, const SkTextBlob*,
                       SkScalar x, SkScalar y,
                       SkDrawFilter*, const SkIRect& clipBounds) override;
 protected:
     GrPathRenderingDrawContext(GrContext* ctx, GrDrawingManager* mgr, GrRenderTarget* rt,
                                const SkSurfaceProps* surfaceProps, GrAuditTrail* at,
                                GrSingleOwner* so)
-        : INHERITED(ctx, mgr, rt, surfaceProps, at, so)
-        , fStencilAndCoverTextContext(nullptr) {}
+        : INHERITED(ctx, mgr, rt, surfaceProps, at, so) {}
 
 private:
-    GrStencilAndCoverTextContext* fStencilAndCoverTextContext;
+    SkAutoTDelete<GrStencilAndCoverTextContext> fStencilAndCoverTextContext;
 
     friend class GrDrawingManager; // for ctor
 
     typedef GrDrawContext INHERITED;
 };
 
 #endif