Remove instant confirmation dialog that is displayed the first time the instant checkbox is clicked.

chrome/common/pref_names.cc

Index: chrome/common/pref_names.cc
diff --git a/chrome/common/pref_names.cc b/chrome/common/pref_names.cc
index 9d275e7c585e1913e081a383ed474ba6964ca911..74f9a84cb069f5cf4ee5e1119dce9cf5b1d09948 100644
--- a/chrome/common/pref_names.cc
+++ b/chrome/common/pref_names.cc
@@ -483,9 +483,6 @@ const char kUrlBlacklist[] = "policy.url_blacklist";
 // Allows access to the listed host patterns, as exceptions to the blacklist.
 const char kUrlWhitelist[] = "policy.url_whitelist";
 
-// Boolean pref indicating whether the instant confirm dialog has been shown.
-const char kInstantConfirmDialogShown[] = "instant.confirm_dialog_shown";
-
 // Boolean pref indicating if instant is enabled.
 const char kInstantEnabled[] = "instant.enabled";