retool image cache to be generic cache

bench/ImageCacheBench.cpp

Index: bench/ImageCacheBench.cpp
diff --git a/bench/ImageCacheBench.cpp b/bench/ImageCacheBench.cpp
index 07f332baa22d5cb5e923ac625ce086a9e0c158fc..f4d88da0424d75a0c11f9f9495ee63f8dbbde59d 100644
--- a/bench/ImageCacheBench.cpp
+++ b/bench/ImageCacheBench.cpp
@@ -19,6 +19,15 @@ public:
         this->init(sizeof(fPtr) + sizeof(fValue));
     }
 };
+struct TestRec : public SkScaledImageCache::Rec {
+    TestKey     fKey;
+    intptr_t    fValue;
+
+    TestRec(const TestKey& key, intptr_t value) : fKey(key), fValue(value) {}
+
+    virtual const Key& getKey() const SK_OVERRIDE { return fKey; }
+    virtual size_t bytesUsed() const SK_OVERRIDE { return sizeof(fKey) + sizeof(fValue); }
+};
 }
 
 class ImageCacheBench : public Benchmark {
@@ -36,10 +45,7 @@ public:
 
     void populateCache() {
         for (int i = 0; i < CACHE_COUNT; ++i) {
-            TestKey key(i);
-            SkBitmap tmp;
-            tmp.allocN32Pixels(1, 1);
-            fCache.unlock(fCache.addAndLock(key, tmp));
+            fCache.unlock(fCache.addAndLock(SkNEW_ARGS(TestRec, (TestKey(i), i))));
         }
     }
 
@@ -54,10 +60,9 @@ protected:
         }
 
         TestKey key(-1);
-        SkBitmap tmp;
-        // search for a miss (-1 scale)
+        // search for a miss (-1)
         for (int i = 0; i < loops; ++i) {
-            SkDEBUGCODE(SkScaledImageCache::ID* id =) fCache.findAndLock(key, &tmp);
+            SkDEBUGCODE(SkScaledImageCache::ID id =) fCache.findAndLock(key);
             SkASSERT(NULL == id);
         }
     }