Allow custom resources in the GrContext's cache

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 881 matching lines @@
     GrStencilBuffer* findStencilBuffer(int width, int height, int sampleCnt);
 
     GrPathRenderer* getPathRenderer(
                     const SkPath& path,
                     const SkStrokeRec& stroke,
                     const GrDrawTarget* target,
                     bool allowSW,
                     GrPathRendererChain::DrawType drawType = GrPathRendererChain::kColor_DrawType,
                     GrPathRendererChain::StencilSupport* stencilSupport = NULL);
 
+    /**
+     * Client code can store custom resources in the cache using
+     * addResourceToCache() and findCachedResource(). findCachedResource() does
+     * not modify the object's ref count, so the caller does not need to call
+     * unref().

[bsalomon, 2014/04/30 20:19:52]

I think this has to ref the object to be safe. What if it gets dropped from the
cache after the find? Won't the caller be holding a dead ptr?

[Chris Dalton, 2014/04/30 21:11:29]

Right, that wording is confusing come to think of it. The usage I intended was
that findCachedResource doesn't ref the object, and if the caller plans to use
it at a future time, they are responsible to ref it. (That's the same behavior
as GrResourceCache::find.)

Does that seem reasonable, or would you rather ref the object for this method?

+     */
+    void addResourceToCache(const GrResourceKey&, GrCacheable*);
+    GrCacheable* findCachedResource(const GrResourceKey& key);
+
 
 #if GR_CACHE_STATS
     void printCacheStats() const;
 #endif
 
 private:
     // Used to indicate whether a draw should be performed immediately or queued in fDrawBuffer.
     enum BufferedDraw {
         kYes_BufferedDraw,
         kNo_BufferedDraw,
@@ skipping 177 matching lines @@
     }
 
     GrTexture* texture() { return fTexture; }
 
 private:
     GrContext*                    fContext;
     GrTexture*                    fTexture;
 };
 
 #endif