Plumb in flag for reusing scratch textures

include/gpu/GrContext.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 GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 66 matching lines @@
      * The 'info' parameter will be stored and passed to the callback function.
      */
     void addCleanUp(PFCleanUpFunc cleanUp, void* info) {
         CleanUpData* entry = fCleanUpData.push();
 
         entry->fFunc = cleanUp;
         entry->fInfo = info;
     }
 
     /**
+     * Change the context's scratch texture reuse behavior. On some platforms

[bsalomon, 2013/07/18 18:12:08]

Do we need this function at all? Do we need anything external to GrContext to
control this?

+     * reusing scratch textures can cause the driver to ghost the texture 
+     * which, in excess, can lead to out of memory problems
+     */
+    void setReuseScratchTextures(bool reuseScratchTextures) { 
+        fReuseScratchTextures = reuseScratchTextures; 
+    }
+
+    /**
      * Abandons all GPU resources, assumes 3D API state is unknown. Call this
      * if you have lost the associated GPU context, and thus internal texture,
      * buffer, etc. references/IDs are now invalid. Should be called even when
      * GrContext is no longer going to be used for two reasons:
      *  1) ~GrContext will not try to free the objects in the 3D API.
      *  2) If you've created GrResources that outlive the GrContext they will
      *     be marked as invalid (GrResource::isValid()) and won't attempt to
      *     free their underlying resource in the 3D API.
      * Content drawn since the last GrContext::flush() may be lost.
      */
@@ skipping 762 matching lines @@
     GrIndexBufferAllocPool*         fDrawBufferIBAllocPool;
     GrInOrderDrawBuffer*            fDrawBuffer;
 
     GrAARectRenderer*               fAARectRenderer;
     GrOvalRenderer*                 fOvalRenderer;
 
     bool                            fDidTestPMConversions;
     int                             fPMToUPMConversion;
     int                             fUPMToPMConversion;
 
+    bool                            fReuseScratchTextures;

[bsalomon, 2013/07/18 18:12:08]

Do we need this or can it just look at the GrGpu's caps?

+
     struct CleanUpData {
         PFCleanUpFunc fFunc;
         void*         fInfo;
     };
 
     SkTDArray<CleanUpData>      fCleanUpData;
 
     GrContext(); // init must be called after the constructor.
     bool init(GrBackend, GrBackendContext);
 
@@ skipping 122 matching lines @@
     }
 
     GrTexture* texture() { return fTexture; }
 
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 
 #endif