Use the correct null constants for Mach threads, tasks, and hosts

util/mach/exc_client_variants.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 26 matching lines @@
 //! function does not do anything with the new thread state returned for these
 //! \a behavior values. Callers that wish to make use of the new thread state
 //! may do so by using the returned \a flavor, \a new_state, and \a
 //! new_state_count values. Thread states may be set by calling
 //! `thread_set_state()` if needed.
 //!
 //! \a thread and \a task are only used when \a behavior indicates that the
 //! exception message will carry identity information, when it has the value
 //! value `EXCEPTION_DEFAULT` or `EXCEPTION_STATE_IDENTITY`, possibly with
 //! `MACH_EXCEPTION_CODES` also set. In other cases, these parameters are unused
-//! and may be set to `MACH_PORT_NULL`.
+//! and may be set to `THREAD_NULL` and `TASK_NULL`, respectively.
 //!
 //! \a flavor, \a old_state, \a old_state_count, \a new_state, and \a
 //! new_state_count are only used when \a behavior indicates that the exception
 //! message will carry thread state information, when it has the value
 //! `EXCEPTION_STATE` or `EXCEPTION_STATE_IDENTITY`, possibly with
 //! `MACH_EXCEPTION_CODES` also set. In other cases, these parameters are unused
 //! and may be set to `0` (\a old_state_count) or `NULL` (the remaining
 //! parameters).
 //!
 //! \param[in] behavior The exception behavior, which dictates which function
@@ skipping 16 matching lines @@
                                       mach_msg_type_number_t code_count,
                                       thread_state_flavor_t* flavor,
                                       const natural_t* old_state,
                                       mach_msg_type_number_t old_state_count,
                                       thread_state_t new_state,
                                       mach_msg_type_number_t* new_state_count);
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_UTIL_MACH_EXC_CLIENT_VARIANTS_H_