expose generalized imagecache key

src/core/SkBitmapCache.h

+/*
+ * Copyright 2014 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef SkBitmapCache_DEFINED
+#define SkBitmapCache_DEFINED
+
+#include "SkScaledImageCache.h"
+
+class SkBitmapCache {
+public:
+    typedef SkScaledImageCache::ID ID;
+
+    static void Unlock(ID* id) {
+        SkScaledImageCache::Unlock(id);
+    }
+
+    /* Input: bitmap+inverse_scale */
+    static ID* FindAndLock(const SkBitmap& src, SkScalar invScaleX, SkScalar invScaleY,
+                           SkBitmap* result);
+    static ID* AddAndLock(const SkBitmap& src, SkScalar invScaleX, SkScalar invScaleY,
+                          const SkBitmap& result);
+
+    /* Input: bitmap_genID+width+height */
+    static ID* FindAndLock(uint32_t genID, int width, int height, SkBitmap* result);
+
+    static ID* AddAndLock(uint32_t genID, int width, int height, const SkBitmap& result);
+};
+
+class SkMipMapCache {
+public:
+    typedef SkScaledImageCache::ID ID;
+
+    static void Unlock(ID* id) {
+        SkScaledImageCache::Unlock(id);
+    }
+
+    static ID* FindAndLock(const SkBitmap& src, const SkMipMap** result);
+    static ID* AddAndLock(const SkBitmap& src, const SkMipMap* result);
+};
+
+#endif