Retract GrRenderTarget from GrTestTarget

include/gpu/GrDrawContext.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawContext_DEFINED
 #define GrDrawContext_DEFINED
 
@@ skipping 278 matching lines @@
     GrAuditTrail* auditTrail() { return fAuditTrail; }
 
     SkDEBUGCODE(GrSingleOwner* singleOwner() { return fSingleOwner; })
     SkDEBUGCODE(void validate() const;)
 
 private:
     friend class GrAtlasTextBlob; // for access to drawBatch
     friend class GrStencilAndCoverTextContext; // for access to drawBatch
     friend class GrDrawingManager; // for ctor
     friend class GrDrawContextPriv;
+    friend class GrTestTarget;  // for access to getDrawTarget
 
     bool drawFilledDRRect(const GrClip& clip,
                           const GrPaint& paint,
                           const SkMatrix& viewMatrix,
                           const SkRRect& origOuter,
                           const SkRRect& origInner);
 
     GrDrawBatch* getFillRectBatch(const GrPaint& paint,
                                   const SkMatrix& viewMatrix,
                                   const SkRect& rect);
@@ skipping 20 matching lines @@
     GrContext*                        fContext;
 
     SkSurfaceProps                    fSurfaceProps;
     GrAuditTrail*                     fAuditTrail;
 
     // In debug builds we guard against improper thread handling
     SkDEBUGCODE(mutable GrSingleOwner* fSingleOwner;)
 };
 
 #endif