SupportsUserData is not thread safe
Lets ensure none of its usages are unsafe.
BUG=
Review URL: https://chromiumcodereview.appspot.com/10919137
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@155794 0039d316-1c4b-4281-b951-d872f2087c98
CrOS-Libchrome-Original-Commit: 7d2e5f7627b05eda3ad483b5cd4d656121ade990
diff --git a/base/supports_user_data.h b/base/supports_user_data.h
index e663ed2..4c7cdca 100644
--- a/base/supports_user_data.h
+++ b/base/supports_user_data.h
@@ -10,6 +10,7 @@
#include "base/base_export.h"
#include "base/memory/linked_ptr.h"
#include "base/memory/ref_counted.h"
+#include "base/threading/thread_checker.h"
namespace base {
@@ -35,6 +36,12 @@
void SetUserData(const void* key, Data* data);
void RemoveUserData(const void* key);
+ // SupportsUserData is not thread-safe, and on debug build will assert it is
+ // only used on one thread. Calling this method allows the caller to hand
+ // the SupportsUserData instance across threads. Use only if you are taking
+ // full control of the synchronization of that hand over.
+ void DetachUserDataThread();
+
protected:
virtual ~SupportsUserData();
@@ -43,6 +50,8 @@
// Externally-defined data accessible by key.
DataMap user_data_;
+ // Guards usage of |user_data_|
+ ThreadChecker thread_checker_;
DISALLOW_COPY_AND_ASSIGN(SupportsUserData);
};