FBTF: Clean up some headers in tab_contents_delegate.h.

BUG=none
TEST=none

Review URL: http://codereview.chromium.org/3145001

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@55635 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/extensions/extensions_service.cc b/chrome/browser/extensions/extensions_service.cc
index bfdc6fa4..dcfc4813f 100644
--- a/chrome/browser/extensions/extensions_service.cc
+++ b/chrome/browser/extensions/extensions_service.cc
@@ -13,6 +13,7 @@
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/time.h"
+#include "base/utf_string_conversions.h"
 #include "base/values.h"
 #include "base/version.h"
 #include "chrome/browser/browser_process.h"