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

mojo/common/environment_data.cc

Index: mojo/common/environment_data.cc
diff --git a/mojo/common/environment_data.cc b/mojo/common/environment_data.cc
new file mode 100644
index 0000000000000000000000000000000000000000..0fcef667dc4c37af288f09e3e74c1786e9c4b52a
--- /dev/null
+++ b/mojo/common/environment_data.cc
@@ -0,0 +1,51 @@
+// 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.
+
+#include "mojo/common/environment_data.h"
+
+#include "base/stl_util.h"
+
+namespace mojo {
+namespace common {
+
+// static
+EnvironmentData* EnvironmentData::instance_ = NULL;
+
+EnvironmentData::EnvironmentData() {
+  DCHECK(!instance_);
+  instance_ = this;
+}
+
+EnvironmentData::~EnvironmentData() {
+  instance_ = NULL;
+  DataMap data_map;
+  data_map.swap(data_map_);
+  STLDeleteContainerPairSecondPointers(data_map.begin(), data_map.end());
+}
+
+// static
+EnvironmentData* EnvironmentData::GetInstance() {
+  return instance_;
+}
+
+void EnvironmentData::SetData(const void* key, scoped_ptr<Data> data) {
+  Data* old = NULL;
+  {
+    base::AutoLock auto_lock(data_lock_);
+    old = data_map_[key];
+    if (data)
+      data_map_[key] = data.release();
+    else
+      data_map_.erase(key);
+  }
+  delete old;
+}
+
+EnvironmentData::Data* EnvironmentData::GetData(const void* key) {
+  base::AutoLock auto_lock(data_lock_);
+  return data_map_.count(key) > 0 ? data_map_[key] : NULL;
+}
+
+}  // namespace common
+}  // namespace mojo