expose generalized imagecache key

bench/ImageCacheBench.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "Benchmark.h"
 #include "SkScaledImageCache.h"
 
+namespace {
+static void* gGlobalAddress;
+class TestKey : public SkScaledImageCache::Key {
+public:
+    void*    fPtr;
+    intptr_t fValue;
+
+    TestKey(intptr_t value) : fPtr(&gGlobalAddress), fValue(value) {
+        this->init(sizeof(fPtr) + sizeof(fValue));
+    }
+};
+}
+
 class ImageCacheBench : public Benchmark {
     SkScaledImageCache  fCache;
     SkBitmap            fBM;
 
     enum {
         DIM = 1,
         CACHE_COUNT = 500
     };
 public:
     ImageCacheBench()  : fCache(CACHE_COUNT * 100) {
         fBM.allocN32Pixels(DIM, DIM);
     }
 
     void populateCache() {
-        SkScalar scale = 1;
         for (int i = 0; i < CACHE_COUNT; ++i) {
+            TestKey key(i);
             SkBitmap tmp;
             tmp.allocN32Pixels(1, 1);
-            fCache.unlock(fCache.addAndLock(fBM, scale, scale, tmp));
-            scale += 1;
+            fCache.unlock(fCache.addAndLock(key, tmp));
         }
     }
 
 protected:
     virtual const char* onGetName() SK_OVERRIDE {
         return "imagecache";
     }
 
     virtual void onDraw(const int loops, SkCanvas*) SK_OVERRIDE {
         if (fCache.getTotalBytesUsed() == 0) {
             this->populateCache();
         }
 
+        TestKey key(-1);
         SkBitmap tmp;
         // search for a miss (-1 scale)
         for (int i = 0; i < loops; ++i) {
-            (void)fCache.findAndLock(fBM, -1, -1, &tmp);
+            SkDEBUGCODE(SkScaledImageCache::ID* id =) fCache.findAndLock(key, &tmp);
+            SkASSERT(NULL == id);
         }
     }
 
 private:
     typedef Benchmark INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 DEF_BENCH( return new ImageCacheBench(); )