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

tools/clang/blink_gc_plugin/CheckGCRootsVisitor.cpp

Index: tools/clang/blink_gc_plugin/CheckGCRootsVisitor.cpp
diff --git a/tools/clang/blink_gc_plugin/CheckGCRootsVisitor.cpp b/tools/clang/blink_gc_plugin/CheckGCRootsVisitor.cpp
deleted file mode 100644
index ab2d2601bc3e527a39e144b1b0d6ccb022a4f7de..0000000000000000000000000000000000000000
--- a/tools/clang/blink_gc_plugin/CheckGCRootsVisitor.cpp
+++ /dev/null
@@ -1,53 +0,0 @@
-// Copyright 2015 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 "CheckGCRootsVisitor.h"
-
-CheckGCRootsVisitor::CheckGCRootsVisitor() {
-}
-
-CheckGCRootsVisitor::Errors& CheckGCRootsVisitor::gc_roots() {
-  return gc_roots_;
-}
-
-bool CheckGCRootsVisitor::ContainsGCRoots(RecordInfo* info) {
-  for (RecordInfo::Fields::iterator it = info->GetFields().begin();
-       it != info->GetFields().end();
-       ++it) {
-    current_.push_back(&it->second);
-    it->second.edge()->Accept(this);
-    current_.pop_back();
-  }
-  return !gc_roots_.empty();
-}
-
-void CheckGCRootsVisitor::VisitValue(Value* edge) {
-  // TODO: what should we do to check unions?
-  if (edge->value()->record()->isUnion())
-    return;
-
-  // Prevent infinite regress for cyclic part objects.
-  if (visiting_set_.find(edge->value()) != visiting_set_.end())
-    return;
-
-  visiting_set_.insert(edge->value());
-  // If the value is a part object, then continue checking for roots.
-  for (Context::iterator it = context().begin();
-       it != context().end();
-       ++it) {
-    if (!(*it)->IsCollection())
-      return;
-  }
-  ContainsGCRoots(edge->value());
-  visiting_set_.erase(edge->value());
-}
-
-void CheckGCRootsVisitor::VisitPersistent(Persistent* edge) {
-  gc_roots_.push_back(current_);
-}
-
-void CheckGCRootsVisitor::AtCollection(Collection* edge) {
-  if (edge->is_root())
-    gc_roots_.push_back(current_);
-}