Simplify SequencedTaskRunner::{Delete,Releaose}Soon impl

This CL removes SequencedTaskRunner-like type support from DeleteHelper.
There no longer exists such a class, and the removal simplify the
implementation.

[email protected], [email protected], [email protected]
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation

Review-Url: https://codereview.chromium.org/2686033002
Cr-Commit-Position: refs/heads/master@{#449544}
diff --git a/sql/connection.cc b/sql/connection.cc
index ac715ae..0511e11 100644
--- a/sql/connection.cc
+++ b/sql/connection.cc
@@ -12,6 +12,7 @@
 #include <utility>
 
 #include "base/bind.h"
+#include "base/debug/alias.h"
 #include "base/debug/dump_without_crashing.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"