[v8 gc] Introduce a base class for all objects that can have pending activity

third_party/WebKit/Source/bindings/core/v8/V8GCRoot.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8GCRoot.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8GCRoot.cpp b/third_party/WebKit/Source/bindings/core/v8/V8GCRoot.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..d8eda13499703bbe0580c4caef3711d06362f707
--- /dev/null
+++ b/third_party/WebKit/Source/bindings/core/v8/V8GCRoot.cpp
@@ -0,0 +1,33 @@
+// 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 "bindings/core/v8/V8GCRoot.h"
+
+#include "wtf/HashSet.h"
+#include "wtf/ThreadSpecific.h"
+#include "wtf/Threading.h"
+
+namespace blink {
+
+namespace {
+
+HashSet<V8GCRoot*>& gcRoots()
+{
+    DEFINE_THREAD_SAFE_STATIC_LOCAL(ThreadSpecific<HashSet<V8GCRoot*>>, gcRootSet, new ThreadSpecific<HashSet<V8GCRoot*>>());
+    return *gcRootSet;
+}
+
+} // namespace
+
+V8GCRoot::V8GCRoot()
+{
+    gcRoots().add(this);

[jochen (gone - plz use gerrit), 2016/03/16 08:46:38]

we might have to add a ScriptWrappable* parameter to the ctor and store that as
well, as we'll need the ScriptWrappable, and there's no way to cast from
V8GCRoot to ScriptWrappable otherwise

[Marcel Hlopko, 2016/03/16 09:07:40]

I will certainly need a way to get to the ScriptWrappable somehow, ctor
parameter sounds good to me. Any disadvantages that I don't see?

+}
+
+V8GCRoot::~V8GCRoot()
+{
+    gcRoots().remove(this);
+}
+
+} // namespace blink