Add GrResourceCache2.

src/gpu/GrClipMaskCache.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrClipMaskCache_DEFINED
 #define GrClipMaskCache_DEFINED
 
@@ skipping 23 matching lines @@
     bool canReuse(int32_t clipGenID, const SkIRect& bounds) {
 
         SkASSERT(clipGenID != SkClipStack::kWideOpenGenID);
         SkASSERT(clipGenID != SkClipStack::kEmptyGenID);
 
         GrClipStackFrame* back = (GrClipStackFrame*) fStack.back();
 
         // We could reuse the mask if bounds is a subset of last bounds. We'd have to communicate
         // an offset to the caller.
         if (back->fLastMask.texture() &&
+            !back->fLastMask.texture()->wasDestroyed() &&
             back->fLastBound == bounds &&
             back->fLastClipGenID == clipGenID) {
             return true;
         }
 
         return false;
     }
 
     void reset() {
         if (fStack.empty()) {
@@ skipping 118 matching lines @@
     }
 
     void setContext(GrContext* context) {
         fContext = context;
     }
 
     GrContext* getContext() {
         return fContext;
     }
 
-    void releaseResources() {
-
+    //  TODO: Remove this when we hold cache keys instead of refs to textures.
+    void purgeResources() {
         SkDeque::F2BIter iter(fStack);
         for (GrClipStackFrame* frame = (GrClipStackFrame*) iter.next();
                 frame != NULL;
                 frame = (GrClipStackFrame*) iter.next()) {
             frame->reset();
         }
     }
 
 private:
     struct GrClipStackFrame {
@@ skipping 18 matching lines @@
             fLastClipGenID = SkClipStack::kInvalidGenID;
 
             GrTextureDesc desc;
 
             fLastMask.set(NULL, desc);
             fLastBound.setEmpty();
         }
 
         int32_t                 fLastClipGenID;
         // The mask's width & height values are used by GrClipMaskManager to correctly scale the
-        // texture coords for the geometry drawn with this mask.
+        // texture coords for the geometry drawn with this mask. TODO: This should be a cache key
+        // and not a hard ref to a texture.
         GrAutoScratchTexture    fLastMask;
         // fLastBound stores the bounding box of the clip mask in clip-stack space. This rect is
         // used by GrClipMaskManager to position a rect and compute texture coords for the mask.
         SkIRect                 fLastBound;
     };
 
     GrContext*   fContext;
     SkDeque      fStack;
 
     typedef SkNoncopyable INHERITED;
 };
 
 #endif // GrClipMaskCache_DEFINED