Revert of GC plugin: improve error reporting when tracing illegal fields.

tools/clang/blink_gc_plugin/tests/fields_illegal_tracing.cpp

Index: tools/clang/blink_gc_plugin/tests/fields_illegal_tracing.cpp
diff --git a/tools/clang/blink_gc_plugin/tests/fields_illegal_tracing.cpp b/tools/clang/blink_gc_plugin/tests/fields_illegal_tracing.cpp
deleted file mode 100644
index b8310773956b5f34793419142987e615d92d4440..0000000000000000000000000000000000000000
--- a/tools/clang/blink_gc_plugin/tests/fields_illegal_tracing.cpp
+++ /dev/null
@@ -1,23 +0,0 @@
-// Copyright 2016 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 "fields_illegal_tracing.h"
-
-namespace blink {
-
-void PartObject::trace(Visitor* visitor) {
-    visitor->trace(m_obj1);
-    visitor->trace(m_obj2);
-    visitor->trace(m_obj3);
-    visitor->trace(m_obj4);
-}
-
-void HeapObject::trace(Visitor* visitor) {
-    visitor->trace(m_obj1);
-    visitor->trace(m_obj2);
-    visitor->trace(m_obj3);
-    visitor->trace(m_obj4);
-}
-
-}