Revert of move annotations to canvas virtual

src/core/SkAnnotationKeys.h

Index: src/core/SkAnnotationKeys.h
diff --git a/src/core/SkAnnotationKeys.h b/src/core/SkAnnotationKeys.h
deleted file mode 100644
index dff93388074a04b3333acaad57e5782f6205203c..0000000000000000000000000000000000000000
--- a/src/core/SkAnnotationKeys.h
+++ /dev/null
@@ -1,33 +0,0 @@
-/*
- * Copyright 2016 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#ifndef SkAnnotationKeys_DEFINED
-#define SkAnnotationKeys_DEFINED
-
-#include "SkTypes.h"
-
-class SkAnnotationKeys {
-public:
-    /**
-     *  Returns the canonical key whose payload is a URL
-     */
-    static const char* URL_Key();
-
-    /**
-     *  Returns the canonical key whose payload is the name of a destination to
-     *  be defined.
-     */
-    static const char* Define_Named_Dest_Key();
-
-    /**
-     *  Returns the canonical key whose payload is the name of a destination to
-     *  be linked to.
-     */
-    static const char* Link_Named_Dest_Key();
-};
-
-#endif