Remove Mojo bindings environment.

mojo/environment/default_task_tracker_impl.h

Index: mojo/environment/default_task_tracker_impl.h
diff --git a/mojo/environment/default_task_tracker_impl.h b/mojo/environment/default_task_tracker_impl.h
deleted file mode 100644
index 34d7f049d833e053bcf6f17cb3cc0f0e5f86560e..0000000000000000000000000000000000000000
--- a/mojo/environment/default_task_tracker_impl.h
+++ /dev/null
@@ -1,19 +0,0 @@
-// Copyright 2015 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.
-
-#ifndef MOJO_ENVIRONMENT_DEFAULT_TASK_TRACKER_IMPL_H_
-#define MOJO_ENVIRONMENT_DEFAULT_TASK_TRACKER_IMPL_H_
-
-#include "mojo/environment/mojo_environment_impl_export.h"
-#include "mojo/public/cpp/environment/task_tracker.h"
-
-namespace mojo {
-namespace internal {
-
-MOJO_ENVIRONMENT_IMPL_EXPORT const TaskTracker* GetDefaultTaskTracker();
-
-}  // namespace internal
-}  // namespace mojo
-
-#endif  // MOJO_ENVIRONMENT_DEFAULT_TASK_TRACKER_IMPL_H_