Signing in to sync as a different user is redirecting to sync settings

chrome/browser/ui/webui/sync_setup_handler.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_setup_handler.h"
 
 #include "base/basictypes.h"
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
@@ skipping 1189 matching lines @@
 void SyncSetupHandler::DidStopLoading(
     content::RenderViewHost* render_view_host) {
   DCHECK(active_gaia_signin_tab_);
 
   // If the user lands on a page outside of Gaia, assume they have navigated
   // away and are no longer thinking about signing in with this tab.  Treat
   // this as if the user closed the tab. However, don't actually close the tab
   // since the user is doing something with it.  Disconnect and forget about it
   // before closing down the sync setup.
   // The one exception is the expected continue URL.  If the user lands there,
-  // this means sign in was successful.
+  // this means sign in was successful.  Ignore the source parameter in the
+  // continue URL since this user may have changed the state of the
+  // "Let me choose what to sync" checkbox.
   const GURL& url = active_gaia_signin_tab_->GetURL();
   const GURL continue_url =
       SyncPromoUI::GetNextPageURLForSyncPromoURL(
           SyncPromoUI::GetSyncPromoURL(GURL(),
                                        SyncPromoUI::SOURCE_SETTINGS,
                                        false));
+  GURL::Replacements replacements;
+  replacements.ClearQuery();
 
-  if (url != continue_url && !gaia::IsGaiaSignonRealm(url.GetOrigin())) {
+  if (!gaia::IsGaiaSignonRealm(url.GetOrigin()) &&
+      url.ReplaceComponents(replacements) !=
+          continue_url.ReplaceComponents(replacements)) {
     content::WebContentsObserver::Observe(NULL);
     active_gaia_signin_tab_ = NULL;
     CloseSyncSetup();
   }
 }
 
 void SyncSetupHandler::WebContentsDestroyed(
     content::WebContents* web_contents) {
   DCHECK(active_gaia_signin_tab_);
   CloseSyncSetup();
@@ skipping 71 matching lines @@
     if (i != current_profile_index && AreUserNamesEqual(
         cache.GetUserNameOfProfileAtIndex(i), username_utf16)) {
       *error_message = l10n_util::GetStringUTF16(
           IDS_SYNC_USER_NAME_IN_USE_ERROR);
       return false;
     }
   }
 
   return true;
 }