Adds a way to associate key/value pairs with the environment

mojo/common/environment_data.h

Index: mojo/common/environment_data.h
diff --git a/mojo/common/environment_data.h b/mojo/common/environment_data.h
new file mode 100644
index 0000000000000000000000000000000000000000..4440df227ec7177515420b962eff010161569b3d
--- /dev/null
+++ b/mojo/common/environment_data.h
@@ -0,0 +1,52 @@
+// Copyright 2014 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 MOJO_COMMON_ENVIRONMENT_DATA_H_
+#define MOJO_COMMON_ENVIRONMENT_DATA_H_
+
+#include <map>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/synchronization/lock.h"
+#include "mojo/common/mojo_common_export.h"
+
+namespace mojo {
+namespace common {
+
+// EnvironmentData is used to store arbitrary key/value pairs in the
+// environment. The key/value pairs are owned by the Environment and deleted
+// when it is deleted.
+class MOJO_COMMON_EXPORT EnvironmentData {
+ public:
+  class MOJO_COMMON_EXPORT Data {
+   public:
+    Data() {}
+    virtual ~Data() {}
+  };
+
+  EnvironmentData();
+  ~EnvironmentData();
+
+  static EnvironmentData* GetInstance();
+
+  void SetData(const void* key, scoped_ptr<Data> data);
+
+  Data* GetData(const void* key);
+
+ private:
+  typedef std::map<const void*, Data*> DataMap;
+
+  static EnvironmentData* instance_;
+
+  base::Lock data_lock_;
+
+  DataMap data_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(EnvironmentData);
+};
+
+}  // namespace common
+}  // namespace mojo
+
+#endif  // MOJO_COMMON_ENVIRONMENT_DATA_H_