Add ability to retrieve a thread_name given a thread_id.

base/threading/thread_id_name_manager.h

Index: base/threading/thread_id_name_manager.h
diff --git a/base/threading/thread_id_name_manager.h b/base/threading/thread_id_name_manager.h
new file mode 100644
index 0000000000000000000000000000000000000000..e592742e6a348375a3d3de745b6be68d1c04a56d
--- /dev/null
+++ b/base/threading/thread_id_name_manager.h
@@ -0,0 +1,52 @@
+// 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.
+
+#ifndef BASE_THREADING_THREAD_ID_NAME_MANAGER_H_
+#define BASE_THREADING_THREAD_ID_NAME_MANAGER_H_
+
+#include <map>
+#include <string>
+
+#include "base/base_export.h"
+#include "base/basictypes.h"
+#include "base/synchronization/lock.h"
+#include "base/threading/platform_thread.h"
+
+template <typename T> struct DefaultSingletonTraits;
+
+namespace base {
+
+class BASE_EXPORT ThreadIdNameManager {
+ public:
+  static ThreadIdNameManager* GetInstance();
+
+  static const char* GetDefaultInternedString();
+
+  // Set the name for the given id.
+  void SetName(PlatformThreadId id, const char* name);
+
+  // Get the name for the given id.
+  const char* GetName(PlatformThreadId id);
+
+  // Remove the name for the given id.
+  void RemoveName(PlatformThreadId id);
+
+ private:
+  friend struct DefaultSingletonTraits<ThreadIdNameManager>;
+
+  ThreadIdNameManager();
+  ~ThreadIdNameManager();
+
+  // lock_ protects both the thread_id_to_name_ and name_to_interned_name_ maps.
+  Lock lock_;
+
+  std::map<PlatformThreadId, std::string*> thread_id_to_interned_name_;
+  std::map<std::string, std::string*> name_to_interned_name_;
+
+  DISALLOW_COPY_AND_ASSIGN(ThreadIdNameManager);
+};
+
+}  // namespace base
+
+#endif  // BASE_THREADING_THREAD_ID_NAME_MANAGER_H_