Make ThreadChecker::CalledOnValidThread() return true when called from the same task.

base/threading/thread_checker_impl.cc

 // Copyright (c) 2011 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 "base/threading/thread_checker_impl.h"
 
 #include "base/threading/thread_task_runner_handle.h"
 
 namespace base {
 
 ThreadCheckerImpl::ThreadCheckerImpl() {
   AutoLock auto_lock(lock_);
   EnsureAssigned();
 }
 
 ThreadCheckerImpl::~ThreadCheckerImpl() = default;
 
 bool ThreadCheckerImpl::CalledOnValidThread() const {
   AutoLock auto_lock(lock_);
   EnsureAssigned();
 
+  // Always return true when called from the task from which this
+  // ThreadCheckerImpl was assigned to a thread.
+  if (task_token_ == TaskToken::GetForCurrentThread())
+    return true;
+
   // If this ThreadCheckerImpl is bound to a valid SequenceToken, it must be
   // equal to the current SequenceToken and there must be a registered
   // ThreadTaskRunnerHandle. Otherwise, the fact that the current task runs on
   // the thread to which this ThreadCheckerImpl is bound is fortuitous.
   if (sequence_token_.IsValid() &&
       (sequence_token_ != SequenceToken::GetForCurrentThread() ||
        !ThreadTaskRunnerHandle::IsSet())) {
     return false;
   }
 
   return thread_id_ == PlatformThread::CurrentRef();
 }
 
 void ThreadCheckerImpl::DetachFromThread() {
   AutoLock auto_lock(lock_);
   thread_id_ = PlatformThreadRef();
+  task_token_ = TaskToken();
   sequence_token_ = SequenceToken();
 }
 
 void ThreadCheckerImpl::EnsureAssigned() const {
   lock_.AssertAcquired();
   if (!thread_id_.is_null())
     return;
 
   thread_id_ = PlatformThread::CurrentRef();
+  task_token_ = TaskToken::GetForCurrentThread();
   sequence_token_ = SequenceToken::GetForCurrentThread();
 }
 
 }  // namespace base