dom-ui sync: Eliminate jank when customizing sync settings.

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

 // Copyright (c) 2011 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/options/sync_setup_handler.h"
 
 #include "base/json/json_reader.h"
 #include "base/json/json_writer.h"
 #include "base/values.h"
 #include "chrome/browser/google/google_util.h"
@@ skipping 235 matching lines @@
         IDS_SYNC_PASSPHRASE_MSG_EXPLICIT_POSTFIX },
   };
 
   RegisterStrings(localized_strings, resources, arraysize(resources));
 }
 
 void SyncSetupHandler::Initialize() {
 }
 
 void SyncSetupHandler::RegisterMessages() {
-  web_ui_->RegisterMessageCallback("didShowPage",
-      NewCallback(this, &SyncSetupHandler::OnDidShowPage));
-  web_ui_->RegisterMessageCallback("didClosePage",
+  web_ui_->RegisterMessageCallback("SyncSetupDidClosePage",
       NewCallback(this, &SyncSetupHandler::OnDidClosePage));
-  web_ui_->RegisterMessageCallback("SubmitAuth",
+  web_ui_->RegisterMessageCallback("SyncSetupSubmitAuth",
       NewCallback(this, &SyncSetupHandler::HandleSubmitAuth));
-  web_ui_->RegisterMessageCallback("Configure",
+  web_ui_->RegisterMessageCallback("SyncSetupConfigure",
       NewCallback(this, &SyncSetupHandler::HandleConfigure));
-  web_ui_->RegisterMessageCallback("Passphrase",
+  web_ui_->RegisterMessageCallback("SyncSetupPassphrase",
       NewCallback(this, &SyncSetupHandler::HandlePassphraseEntry));
-  web_ui_->RegisterMessageCallback("PassphraseCancel",
+  web_ui_->RegisterMessageCallback("SyncSetupPassphraseCancel",
       NewCallback(this, &SyncSetupHandler::HandlePassphraseCancel));
+  web_ui_->RegisterMessageCallback("SyncSetupAttachHandler",
+      NewCallback(this, &SyncSetupHandler::HandleAttachHandler));
 }
 
 void SyncSetupHandler::ShowGaiaLogin(const DictionaryValue& args) {
   StringValue page("login");
   web_ui_->CallJavascriptFunction(
       "SyncSetupOverlay.showSyncSetupPage", page, args);
 }
 
 void SyncSetupHandler::ShowGaiaSuccessAndClose() {
   web_ui_->CallJavascriptFunction("SyncSetupOverlay.showSuccessAndClose");
@@ skipping 24 matching lines @@
 void SyncSetupHandler::ShowSetupDone(const std::wstring& user) {
   StringValue page("done");
   web_ui_->CallJavascriptFunction(
       "SyncSetupOverlay.showSyncSetupPage", page);
 }
 
 void SyncSetupHandler::SetFlow(SyncSetupFlow* flow) {
   flow_ = flow;
 }
 
-void SyncSetupHandler::OnDidShowPage(const ListValue* args) {
-  DCHECK(web_ui_);
-
-  ProfileSyncService* sync_service =
-      web_ui_->GetProfile()->GetProfileSyncService();
-  if (!sync_service)
-    return;
-
-  flow_ = sync_service->get_wizard().AttachSyncSetupHandler(this);
-}
-
 void SyncSetupHandler::OnDidClosePage(const ListValue* args) {
   if (flow_) {
     flow_->OnDialogClosed(std::string());
     flow_ = NULL;
   }
 }
 
 void SyncSetupHandler::HandleSubmitAuth(const ListValue* args) {
   std::string json;
   if (!args->GetString(0, &json)) {
@@ skipping 57 matching lines @@
   }
 
   DCHECK(flow_);
   flow_->OnPassphraseEntry(passphrase);
 }
 
 void SyncSetupHandler::HandlePassphraseCancel(const ListValue* args) {
   DCHECK(flow_);
   flow_->OnPassphraseCancel();
 }
+
+void SyncSetupHandler::HandleAttachHandler(const ListValue* args) {
+  DCHECK(web_ui_);
+
+  ProfileSyncService* sync_service =
+      web_ui_->GetProfile()->GetProfileSyncService();
+  if (!sync_service)
+    return;
+
+  if (!flow_)
+    flow_ = sync_service->get_wizard().AttachSyncSetupHandler(this);
+}
+