message: In FakeNetworkManager remove MessageHandlerAutoCleanup dependency.
  Post task in a less safer way assuming test won't try to destroy the manager right after starting the updates.
  Cr-Commit-Position: refs/heads/main@{#38007}
diff: #include <vector>
  #include "absl/memory/memory.h"
  -#include "rtc_base/checks.h"
  #include "rtc_base/mdns_responder_interface.h"
  -#include "rtc_base/message_handler.h"
  #include "rtc_base/network.h"
  #include "rtc_base/socket_address.h"
  #include "rtc_base/string_encode.h"
  @@ -31,8 +29,7 @@ const int kFakeIPv4NetworkPrefixLength = 24;
  const int kFakeIPv6NetworkPrefixLength = 64;
  // Fake network manager that allows us to manually specify the IPs to use.
  -class FakeNetworkManager : public NetworkManagerBase,
  - public MessageHandlerAutoCleanup {
  +class FakeNetworkManager : public NetworkManagerBase {
  public:
  FakeNetworkManager() {}
  @@ -77,28 +74,14 @@ class FakeNetworkManager : public NetworkManagerBase,
  ++start_count_;
  if (start_count_ == 1) {
  sent_first_update_ = false;
  - rtc::Thread::Current()->Post(RTC_FROM_HERE, this, kUpdateNetworksMessage);
  - } else {
  - if (sent_first_update_) {
  - rtc::Thread::Current()->Post(RTC_FROM_HERE, this,
  - kSignalNetworksMessage);
  - }
  + Thread::Current()->PostTask([this] { DoUpdateNetworks(); });
  + } else if (sent_first_update_) {
  + Thread::Current()->PostTask([this] { SignalNetworksChanged(); });
  }
  }
  void StopUpdating() override { --start_count_; }
  - // MessageHandler interface.
  - void OnMessage(Message* msg) override {
  - if (msg->message_id == kUpdateNetworksMessage) {
  - DoUpdateNetworks();
  - } else if (msg->message_id == kSignalNetworksMessage) {
  - SignalNetworksChanged();
  - } else {
  - RTC_CHECK(false);
  - }
  - }
  -
  using NetworkManagerBase::set_default_local_addresses;
  using NetworkManagerBase::set_enumeration_permission;
  @@ -148,9 +131,6 @@ class FakeNetworkManager : public NetworkManagerBase,
  int start_count_ = 0;
  bool sent_first_update_ = false;
  - static constexpr uint32_t kUpdateNetworksMessage = 1;
  - static constexpr uint32_t kSignalNetworksMessage = 2;
  -
  std::unique_ptr<webrtc::MdnsResponderInterface> mdns_responder_;
  };
  