[MD settings] lighter weight initializer for protocol handler enabled messages

chrome/browser/ui/webui/settings/protocol_handlers_handler.cc

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/settings/protocol_handlers_handler.h"
 
 #include <memory>
 #include <utility>
 #include <vector>
 
@@ skipping 22 matching lines @@
   notification_registrar_.Add(
       this, chrome::NOTIFICATION_PROTOCOL_HANDLER_REGISTRY_CHANGED,
       content::Source<Profile>(Profile::FromWebUI(web_ui())));
 }
 
 void ProtocolHandlersHandler::OnJavascriptDisallowed() {
   notification_registrar_.RemoveAll();
 }
 
 void ProtocolHandlersHandler::RegisterMessages() {
-  web_ui()->RegisterMessageCallback("initializeProtocolHandlerList",
-      base::Bind(&ProtocolHandlersHandler::HandleInitializeList,
+  web_ui()->RegisterMessageCallback("observeProtocolHandlers",
+      base::Bind(&ProtocolHandlersHandler::HandleObserveProtocolHandlers,
                  base::Unretained(this)));
+  web_ui()->RegisterMessageCallback("observeProtocolHandlersEnabledState",
+      base::Bind(
+          &ProtocolHandlersHandler::HandleObserveProtocolHandlersEnabledState,
+          base::Unretained(this)));
   web_ui()->RegisterMessageCallback("clearDefault",
       base::Bind(&ProtocolHandlersHandler::HandleClearDefault,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("removeHandler",
       base::Bind(&ProtocolHandlersHandler::HandleRemoveHandler,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("setHandlersEnabled",
       base::Bind(&ProtocolHandlersHandler::HandleSetHandlersEnabled,
                  base::Unretained(this)));
   web_ui()->RegisterMessageCallback("setDefault",
@@ skipping 68 matching lines @@
   std::unique_ptr<base::ListValue> ignored_handlers(new base::ListValue());
   GetIgnoredHandlers(ignored_handlers.get());
   CallJavascriptFunction("cr.webUIListenerCallback",
                          base::StringValue("setProtocolHandlers"),
                          handlers);
   CallJavascriptFunction("cr.webUIListenerCallback",
                          base::StringValue("setIgnoredProtocolHandlers"),
                          *ignored_handlers);
 }
 
-void ProtocolHandlersHandler::HandleInitializeList(
+void ProtocolHandlersHandler::HandleObserveProtocolHandlers(
     const base::ListValue* args) {
   AllowJavascript();
   SendHandlersEnabledValue();
   UpdateHandlerList();
 }
 
+void ProtocolHandlersHandler::HandleObserveProtocolHandlersEnabledState(
+    const base::ListValue* args) {
+  AllowJavascript();
+  SendHandlersEnabledValue();
+}
+
 void ProtocolHandlersHandler::SendHandlersEnabledValue() {
   CallJavascriptFunction("cr.webUIListenerCallback",
                          base::StringValue("setHandlersEnabled"),
                          base::FundamentalValue(
                              GetProtocolHandlerRegistry()->enabled()));
 }
 
 void ProtocolHandlersHandler::HandleRemoveHandler(const base::ListValue* args) {
   const base::ListValue* list;
   if (!args->GetList(0, &list)) {
@@ skipping 61 matching lines @@
 void ProtocolHandlersHandler::Observe(
     int type,
     const content::NotificationSource& source,
     const content::NotificationDetails& details) {
   DCHECK_EQ(chrome::NOTIFICATION_PROTOCOL_HANDLER_REGISTRY_CHANGED, type);
   SendHandlersEnabledValue();
   UpdateHandlerList();
 }
 
 }  // namespace settings