sync: Buffer Protocol Events for about:sync page

chrome/browser/ui/webui/sync_internals_message_handler.cc

Index: chrome/browser/ui/webui/sync_internals_message_handler.cc
diff --git a/chrome/browser/ui/webui/sync_internals_message_handler.cc b/chrome/browser/ui/webui/sync_internals_message_handler.cc
index e0b64f9bf081ee10a2ee0ae98086bcf11b3dab83..3896a429ef70778f66cac42815285caa5b161dae 100644
--- a/chrome/browser/ui/webui/sync_internals_message_handler.cc
+++ b/chrome/browser/ui/webui/sync_internals_message_handler.cc
@@ -41,14 +41,10 @@ SyncInternalsMessageHandler::~SyncInternalsMessageHandler() {
 void SyncInternalsMessageHandler::RegisterMessages() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 
-  // Register for ProfileSyncService events.
-  ProfileSyncService* service = GetProfileSyncService();
-  if (service) {
-    service->AddObserver(this);
-    service->AddProtocolEventObserver(this);
-    js_controller_ = service->GetJsController();
-    js_controller_->AddJsEventHandler(this);
-  }
+  web_ui()->RegisterMessageCallback(
+      "registerForEvents",
+      base::Bind(&SyncInternalsMessageHandler::HandleRegisterForEvents,
+                 base::Unretained(this)));
 
   web_ui()->RegisterMessageCallback(
       "requestUpdatedAboutInfo",
@@ -64,6 +60,19 @@ void SyncInternalsMessageHandler::RegisterMessages() {
   RegisterJsControllerCallback("getClientServerTraffic");
 }
 
+void SyncInternalsMessageHandler::HandleRegisterForEvents(
+    const base::ListValue* args) {
+  DCHECK(args->empty());
+
+  ProfileSyncService* service = GetProfileSyncService();
+  if (service) {
+    service->AddObserver(this);
+    service->AddProtocolEventObserver(this);
+    js_controller_ = service->GetJsController();
+    js_controller_->AddJsEventHandler(this);
+  }
+}
+
 void SyncInternalsMessageHandler::HandleRequestUpdatedAboutInfo(
     const base::ListValue* args) {
   DCHECK(args->empty());