Mojo: Make GetDefault{AsyncWaiter,Logger} static methods of Environment.

mojo/environment/default_async_waiter.cc

Index: mojo/environment/default_async_waiter.cc
diff --git a/mojo/environment/default_async_waiter.cc b/mojo/environment/default_async_waiter.cc
deleted file mode 100644
index 092caec91d929f34999c01589dcecee24b7bf6e0..0000000000000000000000000000000000000000
--- a/mojo/environment/default_async_waiter.cc
+++ /dev/null
@@ -1,15 +0,0 @@
-// 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.
-
-#include "mojo/public/cpp/environment/default_async_waiter.h"
-
-#include "mojo/environment/default_async_waiter_impl.h"
-
-namespace mojo {
-
-const MojoAsyncWaiter* GetDefaultAsyncWaiter() {
-  return internal::GetDefaultAsyncWaiterImpl();
-}
-
-}  // namespace mojo