Revert of Move GPU fences into sk_gpu_test

tools/gpu/FenceSync.h

Index: tools/gpu/FenceSync.h
diff --git a/tools/gpu/FenceSync.h b/tools/gpu/FenceSync.h
deleted file mode 100644
index c3f1182621e08bd07bfdb18ca54f735d3d5899e3..0000000000000000000000000000000000000000
--- a/tools/gpu/FenceSync.h
+++ /dev/null
@@ -1,34 +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 FenceSync_DEFINED
-#define FenceSync_DEFINED
-
-#include "SkTypes.h"
-
-namespace sk_gpu_test {
-
-using PlatformFence = intptr_t;
-static constexpr PlatformFence kInvalidPlatformFence = 0;
-
-/*
- * This class provides an interface to interact with fence syncs. A fence sync is an object that the
- * client can insert into the GPU command stream, and then at any future time, wait until all
- * commands that were issued before the fence have completed.
- */
-class FenceSync {
-public:
-    virtual PlatformFence SK_WARN_UNUSED_RESULT insertFence() const = 0;
-    virtual bool waitFence(PlatformFence) const = 0;
-    virtual void deleteFence(PlatformFence) const = 0;
-
-    virtual ~FenceSync() {}
-};
-
-}
-
-#endif