diff --git a/api/proxy.h b/api/proxy.h
index 7ed14d03ea..385992e659 100644
--- a/api/proxy.h
+++ b/api/proxy.h
@@ -60,7 +60,6 @@
 #include "api/scoped_refptr.h"
 #include "rtc_base/event.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/ref_counted_object.h"
 #include "rtc_base/system/rtc_export.h"
 #include "rtc_base/thread.h"
diff --git a/audio/null_audio_poller.h b/audio/null_audio_poller.h
index 9a81426b11..97cd2c7e6c 100644
--- a/audio/null_audio_poller.h
+++ b/audio/null_audio_poller.h
@@ -15,7 +15,6 @@
 
 #include "modules/audio_device/include/audio_device_defines.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/thread_checker.h"
 
 namespace webrtc {
diff --git a/media/base/fake_network_interface.h b/media/base/fake_network_interface.h
index ed82fa686c..7d50ca84bc 100644
--- a/media/base/fake_network_interface.h
+++ b/media/base/fake_network_interface.h
@@ -22,7 +22,6 @@
 #include "rtc_base/critical_section.h"
 #include "rtc_base/dscp.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/thread.h"
 
 namespace cricket {
diff --git a/media/sctp/sctp_transport_unittest.cc b/media/sctp/sctp_transport_unittest.cc
index 4c776ed2b3..a267d4c090 100644
--- a/media/sctp/sctp_transport_unittest.cc
+++ b/media/sctp/sctp_transport_unittest.cc
@@ -23,7 +23,6 @@
 #include "rtc_base/copy_on_write_buffer.h"
 #include "rtc_base/gunit.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/thread.h"
 #include "test/gtest.h"
 
diff --git a/p2p/base/dtls_transport.cc b/p2p/base/dtls_transport.cc
index 538aa86f2c..3eba7c680d 100644
--- a/p2p/base/dtls_transport.cc
+++ b/p2p/base/dtls_transport.cc
@@ -22,7 +22,6 @@
 #include "rtc_base/checks.h"
 #include "rtc_base/dscp.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/rtc_certificate.h"
 #include "rtc_base/ssl_stream_adapter.h"
 #include "rtc_base/stream.h"
diff --git a/p2p/base/pseudo_tcp_unittest.cc b/p2p/base/pseudo_tcp_unittest.cc
index 3afe955783..a7fc9b3e69 100644
--- a/p2p/base/pseudo_tcp_unittest.cc
+++ b/p2p/base/pseudo_tcp_unittest.cc
@@ -23,7 +23,6 @@
 #include "rtc_base/logging.h"
 #include "rtc_base/memory_stream.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/thread.h"
 #include "rtc_base/time_utils.h"
 #include "test/gtest.h"
diff --git a/p2p/base/stun_request.h b/p2p/base/stun_request.h
index b9b7110bec..9a2c3a99d8 100644
--- a/p2p/base/stun_request.h
+++ b/p2p/base/stun_request.h
@@ -19,7 +19,6 @@
 
 #include "api/transport/stun.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/thread.h"
 
diff --git a/p2p/base/turn_server.h b/p2p/base/turn_server.h
index 7308cd529a..0f4fefea84 100644
--- a/p2p/base/turn_server.h
+++ b/p2p/base/turn_server.h
@@ -22,15 +22,14 @@
 #include "p2p/base/port_interface.h"
 #include "rtc_base/async_invoker.h"
 #include "rtc_base/async_packet_socket.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/socket_address.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
+#include "rtc_base/thread.h"
 #include "rtc_base/thread_checker.h"
 
 namespace rtc {
 class ByteBufferWriter;
 class PacketSocketFactory;
-class Thread;
 }  // namespace rtc
 
 namespace cricket {
diff --git a/p2p/client/basic_port_allocator.h b/p2p/client/basic_port_allocator.h
index 2af249341b..1272fab26a 100644
--- a/p2p/client/basic_port_allocator.h
+++ b/p2p/client/basic_port_allocator.h
@@ -20,7 +20,6 @@
 #include "p2p/client/relay_port_factory_interface.h"
 #include "p2p/client/turn_port_factory.h"
 #include "rtc_base/checks.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/network.h"
 #include "rtc_base/system/rtc_export.h"
 #include "rtc_base/thread.h"
diff --git a/pc/datagram_rtp_transport.cc b/pc/datagram_rtp_transport.cc
index 02e7a6f022..388a92090a 100644
--- a/pc/datagram_rtp_transport.cc
+++ b/pc/datagram_rtp_transport.cc
@@ -29,7 +29,6 @@
 #include "rtc_base/checks.h"
 #include "rtc_base/dscp.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/rtc_certificate.h"
 #include "rtc_base/ssl_stream_adapter.h"
 #include "rtc_base/stream.h"
diff --git a/pc/jsep_transport.h b/pc/jsep_transport.h
index 5f7d46f915..6edf0aecee 100644
--- a/pc/jsep_transport.h
+++ b/pc/jsep_transport.h
@@ -37,7 +37,6 @@
 #include "pc/srtp_transport.h"
 #include "pc/transport_stats.h"
 #include "rtc_base/constructor_magic.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/rtc_certificate.h"
 #include "rtc_base/ssl_stream_adapter.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
diff --git a/pc/webrtc_session_description_factory.h b/pc/webrtc_session_description_factory.h
index c707feba00..f70b847b4e 100644
--- a/pc/webrtc_session_description_factory.h
+++ b/pc/webrtc_session_description_factory.h
@@ -26,7 +26,6 @@
 #include "pc/peer_connection_internal.h"
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/rtc_certificate.h"
 #include "rtc_base/rtc_certificate_generator.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
diff --git a/rtc_base/critical_section_unittest.cc b/rtc_base/critical_section_unittest.cc
index e384e9874d..16aefd2740 100644
--- a/rtc_base/critical_section_unittest.cc
+++ b/rtc_base/critical_section_unittest.cc
@@ -26,7 +26,6 @@
 #include "rtc_base/event.h"
 #include "rtc_base/location.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/platform_thread.h"
 #include "rtc_base/thread.h"
 #include "test/gtest.h"
diff --git a/rtc_base/null_socket_server_unittest.cc b/rtc_base/null_socket_server_unittest.cc
index 62c95a41c6..39c16313b1 100644
--- a/rtc_base/null_socket_server_unittest.cc
+++ b/rtc_base/null_socket_server_unittest.cc
@@ -17,7 +17,6 @@
 #include "rtc_base/gunit.h"
 #include "rtc_base/location.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/thread.h"
 #include "rtc_base/time_utils.h"
 #include "test/gtest.h"
diff --git a/rtc_base/openssl_adapter.h b/rtc_base/openssl_adapter.h
index 26b58beab7..c3cab2fd78 100644
--- a/rtc_base/openssl_adapter.h
+++ b/rtc_base/openssl_adapter.h
@@ -21,7 +21,6 @@
 #include "rtc_base/async_socket.h"
 #include "rtc_base/buffer.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/openssl_identity.h"
 #include "rtc_base/openssl_session_cache.h"
 #include "rtc_base/socket.h"
diff --git a/rtc_base/openssl_stream_adapter.h b/rtc_base/openssl_stream_adapter.h
index dfe57a441e..67f0ab73bc 100644
--- a/rtc_base/openssl_stream_adapter.h
+++ b/rtc_base/openssl_stream_adapter.h
@@ -20,7 +20,6 @@
 #include <vector>
 
 #include "rtc_base/buffer.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/openssl_identity.h"
 #include "rtc_base/ssl_identity.h"
 #include "rtc_base/ssl_stream_adapter.h"
diff --git a/rtc_base/rtc_certificate_generator.cc b/rtc_base/rtc_certificate_generator.cc
index 2a84fbdb44..cd9cccedf7 100644
--- a/rtc_base/rtc_certificate_generator.cc
+++ b/rtc_base/rtc_certificate_generator.cc
@@ -19,7 +19,6 @@
 #include "rtc_base/checks.h"
 #include "rtc_base/location.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/ref_counted_object.h"
 #include "rtc_base/ssl_identity.h"
 
diff --git a/rtc_base/signal_thread.h b/rtc_base/signal_thread.h
index 9a20ad252b..d9e8ade9b0 100644
--- a/rtc_base/signal_thread.h
+++ b/rtc_base/signal_thread.h
@@ -17,7 +17,6 @@
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/critical_section.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/thread.h"
 #include "rtc_base/thread_annotations.h"
diff --git a/rtc_base/socket_unittest.cc b/rtc_base/socket_unittest.cc
index 7d91cbefca..80b28bb8fa 100644
--- a/rtc_base/socket_unittest.cc
+++ b/rtc_base/socket_unittest.cc
@@ -26,7 +26,6 @@
 #include "rtc_base/location.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/net_helpers.h"
 #include "rtc_base/socket_address.h"
 #include "rtc_base/socket_server.h"
diff --git a/rtc_base/stream.cc b/rtc_base/stream.cc
index ec75b619c1..1b0a4d759b 100644
--- a/rtc_base/stream.cc
+++ b/rtc_base/stream.cc
@@ -17,7 +17,6 @@
 
 #include "rtc_base/checks.h"
 #include "rtc_base/location.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/thread.h"
 
 namespace rtc {
diff --git a/rtc_base/stream.h b/rtc_base/stream.h
index 9147dadd0c..bfb9dc2c41 100644
--- a/rtc_base/stream.h
+++ b/rtc_base/stream.h
@@ -17,9 +17,9 @@
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/critical_section.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/system/rtc_export.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
+#include "rtc_base/thread.h"
 
 namespace rtc {
 
@@ -49,8 +49,6 @@ enum StreamResult { SR_ERROR, SR_SUCCESS, SR_BLOCK, SR_EOS };
 //  SE_WRITE: Data can be written, so Write is likely to not return SR_BLOCK
 enum StreamEvent { SE_OPEN = 1, SE_READ = 2, SE_WRITE = 4, SE_CLOSE = 8 };
 
-class Thread;
-
 struct StreamEventData : public MessageData {
   int events, error;
   StreamEventData(int ev, int er) : events(ev), error(er) {}
diff --git a/rtc_base/virtual_socket_server.h b/rtc_base/virtual_socket_server.h
index 6d6d18a3dd..bbe3f3db6c 100644
--- a/rtc_base/virtual_socket_server.h
+++ b/rtc_base/virtual_socket_server.h
@@ -18,7 +18,7 @@
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/event.h"
 #include "rtc_base/fake_clock.h"
-#include "rtc_base/message_queue.h"
+#include "rtc_base/message_handler.h"
 #include "rtc_base/socket_server.h"
 
 namespace rtc {
diff --git a/rtc_base/virtual_socket_unittest.cc b/rtc_base/virtual_socket_unittest.cc
index 8115c23828..b274b40857 100644
--- a/rtc_base/virtual_socket_unittest.cc
+++ b/rtc_base/virtual_socket_unittest.cc
@@ -32,7 +32,6 @@
 #include "rtc_base/location.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/message_handler.h"
-#include "rtc_base/message_queue.h"
 #include "rtc_base/socket.h"
 #include "rtc_base/socket_address.h"
 #include "rtc_base/test_client.h"