[MessageLoop] Fix IWYU for (SingleThread|Sequenced)TaskRunner

Precursor to land https://chromium-review.googlesource.com/c/chromium/src/+/1035788

Scripted used @ https://crbug.com/825327#c152

[email protected]
[email protected]

Bug: 825327
Cq-Include-Trybots: luci.chromium.try:android_optional_gpu_tests_rel;luci.chromium.try:linux_optional_gpu_tests_rel;luci.chromium.try:mac_optional_gpu_tests_rel;luci.chromium.try:win_optional_gpu_tests_rel;master.tryserver.blink:linux_trusty_blink_rel;master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2;master.tryserver.chromium.linux:linux_mojo;master.tryserver.chromium.linux:linux_vr;master.tryserver.chromium.mac:ios-simulator-cronet;master.tryserver.chromium.mac:ios-simulator-full-configs;master.tryserver.chromium.win:win10_chromium_x64_rel_ng
Change-Id: I5a356e8004b633283a0615a73bb52ed703d97965
Reviewed-on: https://chromium-review.googlesource.com/1035807
Reviewed-by: Gabriel Charette <[email protected]>
Reviewed-by: François Doray <[email protected]>
Commit-Queue: Gabriel Charette <[email protected]>
Cr-Commit-Position: refs/heads/master@{#554924}
diff --git a/ipc/ipc_sync_channel.cc b/ipc/ipc_sync_channel.cc
index 05d04ba..e4a5c8f 100644
--- a/ipc/ipc_sync_channel.cc
+++ b/ipc/ipc_sync_channel.cc
@@ -17,6 +17,7 @@
 #include "base/memory/ptr_util.h"
 #include "base/message_loop/message_loop.h"
 #include "base/run_loop.h"
+#include "base/sequenced_task_runner.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/threading/thread_local.h"
 #include "base/threading/thread_task_runner_handle.h"