Remove the task tracking stuff in the bindings.

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

-// 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.
-
-#include "mojo/public/cpp/environment/lib/scoped_task_tracking.h"
-
-#include "mojo/public/cpp/environment/environment.h"
-
-namespace mojo {
-namespace internal {
-
-ScopedTaskTracking::ScopedTaskTracking(const char* function_name,
-                                       const char* file_name,
-                                       int line,
-                                       const void* program_counter)
-    : id_(Environment::GetDefaultTaskTracker()->StartTracking(
-          function_name,
-          file_name,
-          line,
-          program_counter)) {
-}
-
-ScopedTaskTracking::ScopedTaskTracking(const char* function_name,
-                                       const char* file_name,
-                                       int line)
-    : id_(Environment::GetDefaultTaskTracker()->StartTracking(function_name,
-                                                              file_name,
-                                                              line,
-                                                              nullptr)) {
-}
-
-ScopedTaskTracking::~ScopedTaskTracking() {
-  Environment::GetDefaultTaskTracker()->EndTracking(id_);
-}
-
-}  // namespace internal
-}  // namespace mojo