Fix copyright headers in base/allocator/allocator_check.cc

Follow-up to crrev.com/1577883002. Wrong copyright headers.

BUG=564618
[email protected]

Review URL: https://codereview.chromium.org/1584803002

Cr-Commit-Position: refs/heads/master@{#369153}
diff --git a/base/allocator/allocator_check.cc b/base/allocator/allocator_check.cc
index 4220fb79..a708f0f 100644
--- a/base/allocator/allocator_check.cc
+++ b/base/allocator/allocator_check.cc
@@ -1,4 +1,4 @@
-// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.