[TaskScheduler] Remove temporary forwarding headers and mass migrate users

When this CL is approved I will rebase it on top of tree and mass
migrate all callers in a new patch set (TBR'ed change).

[email protected] (for mass migration of existing callers)

Bug: 867421
Change-Id: I41092bbc4824964ee047e0bf53e972c8f6e896a4
Reviewed-on: https://chromium-review.googlesource.com/1161116
Commit-Queue: Gabriel Charette <[email protected]>
Reviewed-by: Gabriel Charette <[email protected]>
Reviewed-by: Sami Kyöstilä <[email protected]>
Cr-Commit-Position: refs/heads/master@{#580845}
diff --git a/components/update_client/crx_downloader.cc b/components/update_client/crx_downloader.cc
index ff5f424..7af00a8 100644
--- a/components/update_client/crx_downloader.cc
+++ b/components/update_client/crx_downloader.cc
@@ -10,8 +10,8 @@
 #include "base/files/file_util.h"
 #include "base/location.h"
 #include "base/logging.h"
-#include "base/task/post_task_forward.h"
-#include "base/task/task_traits_forward.h"
+#include "base/task/post_task.h"
+#include "base/task/task_traits.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "build/build_config.h"
 #if defined(OS_WIN)