Revert of base: Fix/add header #ifndef guards. (patchset #2 id:20001 of https://codereview.chromium.org/985003004/)

Reason for revert:
This seems to be causing tree closing compile failure https://build.chromium.org/p/chromium/builders/Android/builds/36135/steps/compile/logs/stdio.

Original issue's description:
> base: Fix/add header #ifndef guards.
>
> Header guards should be defined based on the path and file name of the
> header file. Some headers have it wrong, some are missing the guards,
> and some just have the matching comment wrong.
>
> R=Nico
> BUG=464816
>
> Committed: https://crrev.com/301b392761fd8f66f3a701ab1dd011c6e7a55e19
> Cr-Commit-Position: refs/heads/master@{#319722}

TBR=thakis@chromium.org,danakj@chromium.org
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=464816

Review URL: https://codereview.chromium.org/989343002

Cr-Commit-Position: refs/heads/master@{#319728}


CrOS-Libchrome-Original-Commit: 2220bd6553b4aae764ed66b24f5aa6e398c70b68
diff --git a/base/sequenced_task_runner.h b/base/sequenced_task_runner.h
index 6bb3f2b..71dcf05 100644
--- a/base/sequenced_task_runner.h
+++ b/base/sequenced_task_runner.h
@@ -2,8 +2,8 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef BASE_SEQUENCED_TASK_RUNNER_H_
-#define BASE_SEQUENCED_TASK_RUNNER_H_
+#ifndef BASE_SEQUENCED_TASKRUNNER_H_
+#define BASE_SEQUENCED_TASKRUNNER_H_
 
 #include "base/base_export.h"
 #include "base/sequenced_task_runner_helpers.h"
@@ -156,4 +156,4 @@
 
 }  // namespace base
 
-#endif  // BASE_SEQUENCED_TASK_RUNNER_H_
+#endif  // BASE_SEQUENCED_TASKRUNNER_H_