Update behavior of one-click infobar to remove modal dialog, add "undo".

chrome/common/url_constants.cc

Index: chrome/common/url_constants.cc
diff --git a/chrome/common/url_constants.cc b/chrome/common/url_constants.cc
index b00a417e251ed706d8e93054e241266f9369cb3c..14a5260460f83a82945a6562ff6cd11a1394086b 100644
--- a/chrome/common/url_constants.cc
+++ b/chrome/common/url_constants.cc
@@ -293,6 +293,13 @@ const char kChromeHelpURL[] =
     "https://support.google.com/chrome/?p=help";
 #endif
 
+const char kChromeSyncLearnMoreURL[] =
+#if defined(OS_CHROMEOS)
+    "http://support.google.com/chromeos/bin/answer.py?hl=en&answer=165139";
+#else
+    "http://support.google.com/chrome/bin/answer.py?hl=en&answer=165139";
+#endif
+
 const char kSettingsSearchHelpURL[] =
 #if defined(OS_CHROMEOS)
     "https://support.google.com/chromeos/?p=settings_search_help";