Begin removing deprecated (and now, unused) ImageFilter code paths

tests/TestingSpecialImageAccess.h

Index: tests/TestingSpecialImageAccess.h
diff --git a/tests/TestingSpecialImageAccess.h b/tests/TestingSpecialImageAccess.h
deleted file mode 100644
index 64a6d29665a39b87e1c2b7b0e81e3c4643d997cf..0000000000000000000000000000000000000000
--- a/tests/TestingSpecialImageAccess.h
+++ /dev/null
@@ -1,18 +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 TestingSpecialImageAccess_DEFINED
-#define TestingSpecialImageAccess_DEFINED
-
-class TestingSpecialImageAccess {
-public:
-    static const SkIRect& Subset(const SkSpecialImage* img) {
-        return img->subset();
-    }
-};
-
-#endif