[Sync UI] Disable the "Advanced..." button when there is an unrecoverable sync error.

chrome/browser/ui/webui/options/personal_options_handler.cc

Index: chrome/browser/ui/webui/options/personal_options_handler.cc
diff --git a/chrome/browser/ui/webui/options/personal_options_handler.cc b/chrome/browser/ui/webui/options/personal_options_handler.cc
index acc3da77aed09d28fff24dbe2435129e763d00b2..d99dda7ce1b21966cd95425481d79359b90f16e4 100644
--- a/chrome/browser/ui/webui/options/personal_options_handler.cc
+++ b/chrome/browser/ui/webui/options/personal_options_handler.cc
@@ -309,6 +309,12 @@ void PersonalOptionsHandler::OnStateChanged() {
   web_ui_->CallJavascriptFunction("PersonalOptions.setSyncStatusErrorVisible",
                                   *visible);
 
+  enabled.reset(Value::CreateBooleanValue(
+      !service->unrecoverable_error_detected()));
+  web_ui_->CallJavascriptFunction(
+      "PersonalOptions.setCustomizeSyncButtonEnabled",
+      *enabled);
+
   if (CommandLine::ForCurrentProcess()->HasSwitch(switches::kEnableAutologin)) {
     visible.reset(Value::CreateBooleanValue(
         service->AreCredentialsAvailable()));