[Garbled Text][Infobar] Adding infobar to suggest turning on encoding detection.

chrome/browser/infobars/infobar_delegate.cc

Index: chrome/browser/infobars/infobar_delegate.cc
diff --git a/chrome/browser/infobars/infobar_delegate.cc b/chrome/browser/infobars/infobar_delegate.cc
index a8d5c4f5a129c3ca7c1e33303dc2f59cf516d48a..526a726e55044102a30a780ebe3e04d77c997cdf 100644
--- a/chrome/browser/infobars/infobar_delegate.cc
+++ b/chrome/browser/infobars/infobar_delegate.cc
@@ -54,6 +54,10 @@ ExtensionInfoBarDelegate* InfoBarDelegate::AsExtensionInfoBarDelegate() {
   return NULL;
 }
 
+GarbledTextInfoBarDelegate* InfoBarDelegate::AsGarbledTextInfoBarDelegate() {
+  return NULL;
+}
+
 InsecureContentInfoBarDelegate*
     InfoBarDelegate::AsInsecureContentInfoBarDelegate() {
   return NULL;