Content Shell: Typo in header.

Oooh. I am stupid, and I have no idea how this compiled. :)

BUG=420994
TBR=marja@chromium.org

Review URL: https://codereview.chromium.org/660473003

Cr-Commit-Position: refs/heads/master@{#300434}

content/shell/browser/layout_test/layout_test_browser_main.cc

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "content/shell/browser/shell_browser_main.h"
+#include "content/shell/browser/layout_test/layout_test_browser_main.h"
 
 #include <iostream>