Optimize CSS box-shadow performance

src/core/SkMaskCache.h

Index: src/core/SkMaskCache.h
diff --git a/src/core/SkMaskCache.h b/src/core/SkMaskCache.h
new file mode 100644
index 0000000000000000000000000000000000000000..a0ad1351659e378058a87d04466a70c3cdd10957
--- /dev/null
+++ b/src/core/SkMaskCache.h
@@ -0,0 +1,24 @@
+/*
+ * 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 SkMaskCache_DEFINED
+#define SkMaskCache_DEFINED
+
+#include "SkMask.h"
+#include "SkRect.h"
+#include "SkRRect.h"
+
+class SkMaskCache {
+public:
+    static bool Find(SkScalar sigma, const SkRRect& rrect, SkMask* result);
+    static void Add(SkScalar sigma, const SkRRect& rrect, const SkMask& mask);
+
+    static bool Find(SkScalar sigma, int32_t count, const SkRect rects[], SkMask* result);
+    static void Add(SkScalar sigma, int32_t count, const SkRect rects[], const SkMask& mask);
+};
+
+#endif