Loosen requirement that there be only one GrDrawTarget

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 31 matching lines @@
 class GrPathRangeDraw;
 
 class GrDrawTarget final : public SkRefCnt {
 public:
     // The context may not be fully constructed and should not be used during GrDrawTarget
     // construction.
     GrDrawTarget(GrGpu* gpu, GrResourceProvider*);
 
     ~GrDrawTarget() override;
 
+    void makeClosed() {
+        // We only close drawTargets When MDB is enabled. When MDB is disabled there is only
+        // ever one drawTarget and all calls will be funnelled into it.
+#ifdef ENABLE_MDB
+        fClosed = true;
+#endif
+    }
+    bool isClosed() const { return fClosed; }
+
     /**
      * Empties the draw buffer of any queued up draws.
      */
     void reset();
 
     /**
      * This plays any queued up draws to its GrGpu target. It also resets this object (i.e. flushing
      * is destructive).
      */
     void flush();
@@ skipping 166 matching lines @@
     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;
     GrBatchFlushState                           fFlushState;
     bool                                        fFlushing;
     int                                         fFirstUnpreparedBatch;
 
+    bool                                        fClosed;
+
     typedef SkRefCnt INHERITED;
 };
 
 #endif