Clean up dead code.

src/ports/SkOSEnvironment.cpp

Index: src/ports/SkOSEnvironment.cpp
diff --git a/src/ports/SkOSEnvironment.cpp b/src/ports/SkOSEnvironment.cpp
deleted file mode 100644
index ec2cc3647d83b00faeda87ae119fbca42ad62c4f..0000000000000000000000000000000000000000
--- a/src/ports/SkOSEnvironment.cpp
+++ /dev/null
@@ -1,18 +0,0 @@
-/*
- * Copyright 2015 Google Inc.
- *
- * Use of this source code is governed by a BSD-style license that can be
- * found in the LICENSE file.
- */
-
-#include "SkOSEnvironment.h"
-#include "SkTypes.h"
-#include <stdlib.h>
-
-void sk_setenv(const char* key, const char* value) {
-#ifdef SK_BUILD_FOR_WIN32
-    _putenv_s(key, value);
-#else
-    setenv(key, value, 1);
-#endif
-}