Remove tools/clang (this will break things temporarily).

tools/clang/blink_gc_plugin/tests/persistent_field_in_gc_managed_class.cpp

Index: tools/clang/blink_gc_plugin/tests/persistent_field_in_gc_managed_class.cpp
diff --git a/tools/clang/blink_gc_plugin/tests/persistent_field_in_gc_managed_class.cpp b/tools/clang/blink_gc_plugin/tests/persistent_field_in_gc_managed_class.cpp
deleted file mode 100644
index 7b3f286aff37e68cf9bce93286467097d6768bf7..0000000000000000000000000000000000000000
--- a/tools/clang/blink_gc_plugin/tests/persistent_field_in_gc_managed_class.cpp
+++ /dev/null
@@ -1,13 +0,0 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "persistent_field_in_gc_managed_class.h"
-
-namespace blink {
-
-void HeapObject::trace(Visitor* visitor) {
-    visitor->trace(m_parts);
-}
-
-}