It seems GAIA had changed dosserver rules today, so we can go back to accounts.google.com.

chrome/browser/ui/webui/sync_promo/sync_promo_ui.cc

 // Copyright (c) 2012 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/sync_promo/sync_promo_ui.h"
 
 #include "base/command_line.h"
 #include "base/string_number_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/first_run/first_run.h"
 #include "chrome/browser/google/google_util.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/profiles/profile_info_cache.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/sync/profile_sync_service.h"
 #include "chrome/browser/sync/profile_sync_service_factory.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "chrome/browser/ui/webui/chrome_web_ui_data_source.h"
 #include "chrome/browser/ui/webui/options2/core_options_handler2.h"
 #include "chrome/browser/ui/webui/sync_promo/sync_promo_handler.h"
 #include "chrome/browser/ui/webui/sync_promo/sync_promo_trial.h"
 #include "chrome/browser/ui/webui/theme_source.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/pref_names.h"
 #include "chrome/common/url_constants.h"
+#include "chrome/common/net/url_util.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_ui.h"
 #include "googleurl/src/url_util.h"
 #include "grit/browser_resources.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "ui/base/l10n/l10n_util.h"
 
 using content::WebContents;
 
@@ skipping 34 matching lines @@
 };
 
 SyncPromoUIHTMLSource::SyncPromoUIHTMLSource(content::WebUI* web_ui)
     : ChromeWebUIDataSource(chrome::kChromeUISyncPromoHost) {
   DictionaryValue localized_strings;
   options2::CoreOptionsHandler::GetStaticLocalizedValues(&localized_strings);
   SyncSetupHandler::GetStaticLocalizedValues(&localized_strings, web_ui);
   AddLocalizedStrings(localized_strings);
 }
 
-// Looks for |search_key| in the query portion of |url|. Returns true if the
-// key is found and sets |out_value| to the value for the key. Returns false if
-// the key is not found.
-bool GetValueForKeyInQuery(const GURL& url, const std::string& search_key,
-                           std::string* out_value) {
-  url_parse::Component query = url.parsed_for_possibly_invalid_spec().query;
-  url_parse::Component key, value;
-  while (url_parse::ExtractQueryKeyValue(
-      url.spec().c_str(), &query, &key, &value)) {
-    if (key.is_nonempty()) {
-      std::string key_string = url.spec().substr(key.begin, key.len);
-      if (key_string == search_key) {
-        if (value.is_nonempty())
-          *out_value = url.spec().substr(value.begin, value.len);
-        else
-          *out_value = "";
-        return true;
-      }
-    }
-  }
-  return false;
-}
-
 }  // namespace
 
 SyncPromoUI::SyncPromoUI(content::WebUI* web_ui) : WebUIController(web_ui) {
   SyncPromoHandler* handler = new SyncPromoHandler(
       g_browser_process->profile_manager());
   web_ui->AddMessageHandler(handler);
 
   // Set up the chrome://theme/ source.
   Profile* profile = Profile::FromWebUI(web_ui);
   ThemeSource* theme = new ThemeSource(profile);
@@ skipping 126 matching lines @@
     std::string escaped_spec(output.data(), output.length());
     stream << "&" << kSyncPromoQueryKeyNextPage << "=" << escaped_spec;
   }
 
   return GURL(stream.str());
 }
 
 // static
 GURL SyncPromoUI::GetNextPageURLForSyncPromoURL(const GURL& url) {
   std::string value;
-  if (GetValueForKeyInQuery(url, kSyncPromoQueryKeyNextPage, &value)) {
-    url_canon::RawCanonOutputT<char16> output;
-    url_util::DecodeURLEscapeSequences(value.c_str(), value.length(), &output);
-    std::string url;
-    UTF16ToUTF8(output.data(), output.length(), &url);
-    return GURL(url);
+  if (chrome_common_net::GetValueForKeyInQuery(
+          url, kSyncPromoQueryKeyNextPage, &value)) {
+    return GURL(value);
   }
   return GURL();
 }
 
 // static
 SyncPromoUI::Source SyncPromoUI::GetSourceForSyncPromoURL(const GURL& url) {
   std::string value;
-  if (GetValueForKeyInQuery(url, kSyncPromoQueryKeySource, &value)) {
+  if (chrome_common_net::GetValueForKeyInQuery(
+          url, kSyncPromoQueryKeySource, &value)) {
     int source = 0;
     if (base::StringToInt(value, &source) && source >= SOURCE_START_PAGE &&
         source < SOURCE_UNKNOWN) {
       return static_cast<Source>(source);
     }
   }
   return SOURCE_UNKNOWN;
 }