Alias deref -> unref. This allows Skia objects to be held by WTF::RefPtr

include/core/SkRefCnt.h

Index: include/core/SkRefCnt.h
diff --git a/include/core/SkRefCnt.h b/include/core/SkRefCnt.h
index c20ef24069371eb58c3c78e010211012e520aa49..6c7d922dfe72515325fc7f672d9beb9d2f5611b4 100644
--- a/include/core/SkRefCnt.h
+++ b/include/core/SkRefCnt.h
@@ -81,6 +81,11 @@ public:
      */
     void Release() { this->unref(); }
 
+    /**
+     * Alias for unref(), for compatibility with WTF::RefPtr.
+     */
+    void deref() { this->unref(); }
+
 protected:
     /**
      *  Allow subclasses to call this if they've overridden internal_dispose