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

mojo/environment/environment.cc

Index: mojo/environment/environment.cc
diff --git a/mojo/environment/environment.cc b/mojo/environment/environment.cc
index 27af33b6ae5d652ceff6b806c54df1c19e2705d7..0c987913c36303da14a3d6e47ba7f4ada70aab54 100644
--- a/mojo/environment/environment.cc
+++ b/mojo/environment/environment.cc
@@ -4,17 +4,32 @@
 
 #include "mojo/public/cpp/environment/environment.h"
 
+#include "mojo/common/environment_data.h"
+
 namespace mojo {
 
-// These methods do nothing as we rely on LazyInstance<T> to instantiate all of
-// our global state in this implementation of the environment library.
+class ChromeEnvironmentImpl : public Environment::Impl {
+ public:
+  ChromeEnvironmentImpl();
+  ~ChromeEnvironmentImpl();
+
+ private:
+  common::EnvironmentData data_;
+
+  DISALLOW_COPY_AND_ASSIGN(ChromeEnvironmentImpl);
+};
+
+ChromeEnvironmentImpl::ChromeEnvironmentImpl() {
+}
+
+ChromeEnvironmentImpl::~ChromeEnvironmentImpl() {
+}
 
-Environment::Environment() {
-  // no-op
+Environment::Environment() : impl_(new ChromeEnvironmentImpl) {
 }
 
 Environment::~Environment() {
-  // no-op
+  delete impl_;
 }
 
 }  // namespace mojo