Switch to standard integer types in components/, part 2 of 4.

components/mus/ws/test_change_tracker.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 "components/mus/ws/test_change_tracker.h"
 
+#include <stddef.h>
+
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "components/mus/common/util.h"
 #include "mojo/common/common_type_converters.h"
 
 using mojo::Array;
 using mojo::String;
 
 namespace mus {
 
@@ skipping 351 matching lines @@
 std::string TestWindow::ToString2() const {
   return base::StringPrintf(
       "window=%s parent=%s visible=%s drawn=%s",
       WindowIdToString(window_id).c_str(), WindowIdToString(parent_id).c_str(),
       visible ? "true" : "false", drawn ? "true" : "false");
 }
 
 }  // namespace ws
 
 }  // namespace mus