Support frame tree propagation between renderers in the same browsing instance.

content/common/content_constants_internal.cc

Index: content/common/content_constants_internal.cc
diff --git a/content/common/content_constants_internal.cc b/content/common/content_constants_internal.cc
new file mode 100644
index 0000000000000000000000000000000000000000..03f638e47ef86964a2999bc7cec699b5ef1b190c
--- /dev/null
+++ b/content/common/content_constants_internal.cc
@@ -0,0 +1,13 @@
+// Copyright (c) 2012 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 "content/common/content_constants_internal.h"
+
+namespace content {
+
+const char kFrameTreeNodeNameKey[] = "name";
+const char kFrameTreeNodeIdKey[] = "id";
+const char kFrameTreeNodeSubtreeKey[] = "subtree";
+
+} // namespace content