Make textures register with GrResourceCache2 as scratch.

src/gpu/GrResourceCache2.h

Index: src/gpu/GrResourceCache2.h
diff --git a/src/gpu/GrResourceCache2.h b/src/gpu/GrResourceCache2.h
index 8e79c09e39e1c798553ff2d0e6cefc0916d05e29..4252edd18582ad96297afdd6dd539c06bd6530ff 100644
--- a/src/gpu/GrResourceCache2.h
+++ b/src/gpu/GrResourceCache2.h
@@ -9,10 +9,10 @@
 #ifndef GrResourceCache2_DEFINED
 #define GrResourceCache2_DEFINED
 
-#include "GrTypes.h"
+#include "GrGpuResource.h"
+#include "GrResourceKey.h"
 #include "SkTInternalLList.h"
-
-class GrGpuResource;
+#include "SkTMultiMap.h"
 
 /**
  *  Eventual replacement for GrResourceCache. Currently it simply holds a list
@@ -39,8 +39,20 @@ private:
     }
 #endif
 
-    int                             fCount;
-    SkTInternalLList<GrGpuResource> fResources;
+
+    void removeScratch(const GrGpuResource* resource);
+    struct ScratchMapTraits {
+        static const GrResourceKey& GetKey(const GrGpuResource& r) {
+            return r.getScratchKey();
+        }
+
+        static uint32_t Hash(const GrResourceKey& key) { return key.getHash(); }
+    };
+    typedef SkTMultiMap<GrGpuResource, GrResourceKey, ScratchMapTraits> ScratchMap;
+
+    int                                 fCount;
+    SkTInternalLList<GrGpuResource>     fResources;

[robertphillips, 2014/08/27 19:11:30]

// All resources that can be used as scratch can be found in 'fScratchMap'.
// The suitability of a potential scratch resource for a particular
// use (e.g., holding a loaded texture) will be determined by
// the pending operations (e.g., pending reads or writes).

?

[bsalomon, 2014/08/27 20:37:40]

I don't think I want to document the whole scratch recycling mechanism here. I
put a simple comment and will add more comments as the functionality comes
online.

+    ScratchMap                          fScratchMap;
 };
 
 #endif