Remove requirement that mojo::Environment be instantiated.

mojo/environment/environment.cc

Index: mojo/environment/environment.cc
diff --git a/mojo/environment/environment.cc b/mojo/environment/environment.cc
index 8867dd088342fc05e6af2788dd129edaefc5e306..cf686958ce5250395283c8d92c14b08591783f52 100644
--- a/mojo/environment/environment.cc
+++ b/mojo/environment/environment.cc
@@ -10,20 +10,6 @@
 
 namespace mojo {
 
-// These methods are intentionally not implemented so that there is a link
-// error if someone uses them in a Chromium-environment.
-#if 0
-Environment::Environment() {
-}
-
-Environment::Environment(const MojoAsyncWaiter* default_async_waiter,
-                         const MojoLogger* default_logger) {
-}
-
-Environment::~Environment() {
-}
-#endif
-
 // static
 const MojoAsyncWaiter* Environment::GetDefaultAsyncWaiter() {
   return &internal::kDefaultAsyncWaiter;