Mojo: Add GetMinimumLogLevel() to the logger interface.

mojo/public/cpp/environment/lib/environment.cc

 // 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/environment.h"
 
+#include "mojo/public/cpp/environment/lib/default_logger_internal.h"
 #include "mojo/public/cpp/utility/run_loop.h"
 
 namespace mojo {
 
 Environment::Environment() {
+  SetMinimumLogLevel(MOJO_LOG_LEVEL_INFO);
   RunLoop::SetUp();
 }
 
 Environment::~Environment() {
   RunLoop::TearDown();
 }
 
+// static
+void Environment::SetMinimumLogLevel(MojoLogLevel minimum_log_level) {
+  internal::SetMinimumLogLevel(minimum_log_level);
+}
+
 }  // namespace mojo