Add Drawing Manager guards against re-entrant flushes

src/gpu/GrDrawTarget.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrDrawTarget_DEFINED
 #define GrDrawTarget_DEFINED
 
@@ skipping 270 matching lines @@
 
     // Used only by CMM.
     void clearStencilClip(const SkIRect&, bool insideClip, GrRenderTarget*);
 
     SkSTArray<256, SkAutoTUnref<GrBatch>, true> fBatches;
     SkAutoTDelete<GrClipMaskManager>            fClipMaskManager;
     // The context is only in service of the clip mask manager, remove once CMM doesn't need this.
     GrContext*                                  fContext;
     GrGpu*                                      fGpu;
     GrResourceProvider*                         fResourceProvider;
-    bool                                        fFlushing;
 
     SkDEBUGCODE(int                             fDebugID;)
     uint32_t                                    fFlags;
 
     // 'this' drawTarget relies on the output of the drawTargets in 'fDependencies'
     SkTDArray<GrDrawTarget*>                    fDependencies;
     GrRenderTarget*                             fRenderTarget;
 
     bool                                        fDrawBatchBounds;
     int                                         fMaxBatchLookback;
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif