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

mojo/public/cpp/environment/lib/default_logger.h

 // 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/application/lib/service_connector.h"
+#ifndef MOJO_PUBLIC_CPP_ENVIRONMENT_LIB_DEFAULT_LOGGER_H_
+#define MOJO_PUBLIC_CPP_ENVIRONMENT_LIB_DEFAULT_LOGGER_H_
+
+struct MojoLogger;
 
 namespace mojo {
 namespace internal {
 
-ServiceConnectorBase::ServiceConnectorBase(const std::string& name)
-    : name_(name),
-      registry_(NULL) {
-}
-
-ServiceConnectorBase::~ServiceConnectorBase() {}
+extern const MojoLogger kDefaultLogger;
 
 }  // namespace internal
 }  // namespace mojo
+
+#endif  // MOJO_PUBLIC_CPP_ENVIRONMENT_LIB_DEFAULT_LOGGER_H_