Make TracedValue lower overhead.

base/traced_object.h

Index: base/traced_object.h
diff --git a/base/traced_object.h b/base/traced_object.h
new file mode 100644
index 0000000000000000000000000000000000000000..4928ff8b0f850c743351d638912276e4aff0c65a
--- /dev/null
+++ b/base/traced_object.h
@@ -0,0 +1,23 @@
+// Copyright 2013 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.
+
+#ifndef BASE_TRACED_OBJECT_H_
+#define BASE_TRACED_OBJECT_H_
+
+#include "base/trace_event_value.h"
+
+namespace base {
+
+class TracedValue;
+
+class BASE_EXPORT TracedObject {
+ public:
+  virtual ~TracedObject() {}

[rterrazas, 2013/07/21 22:23:49]

This is the interface I mentioned, implementing this would allow us to push
objects of whatever type we want into the pickle, and it would separate the core
TracedValue code from classes that need to be traced through it.

Is this a pattern we'd like to adopt?.

[dsinclair, 2013/07/23 14:56:29]

As above, I don't think this is needed. Is there a specific usecase where we
need this over just passing TracedValue's into Push?

+  virtual void PushInto(base::TracedValue* traced_value) const {}
+};
+
+}  // namespace base
+
+#endif  // BASE_TRACED_OBJECT_H_
+