signin: force web signin flow initiated visits to accounts.google.com to their own process.

chrome/browser/ui/sync/one_click_signin_helper.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/sync/one_click_signin_helper.h"
 
 #include <algorithm>
 #include <functional>
 #include <utility>
 #include <vector>
@@ skipping 529 matching lines @@
   if (!profile)
     return false;
 
   if (can_offer_for == CAN_OFFER_FOR_INTERSTITAL_ONLY &&
       !profile->GetPrefs()->GetBoolean(prefs::kReverseAutologinEnabled))
     return false;
 
   if (!SigninManager::AreSigninCookiesAllowed(profile))
     return false;
 
+  SigninManager* manager =
+      SigninManagerFactory::GetForProfile(profile);
+  if (!manager)
+    return false;
+
+  if (!manager->IsSigninProcess(web_contents->GetRenderProcessHost()))
+    return false;

[Roger Tawa OOO till Jul 10th, 2013/02/28 18:23:17]

This check should only be done if there is a valid email.  CanOffer() is called
from BrowserTabContents::AttachTabHelpers() to know if a OneClickSigninHelper
should even be instantiated, and does not pass in an email address.

Move this if statement to line 559 below.

+
   if (!email.empty()) {
-    SigninManager* manager =
-        SigninManagerFactory::GetForProfile(profile);
-    if (!manager)
-      return false;
-
     // If the signin manager already has an authenticated name, then this is a
     // re-auth scenario.  Make sure the email just signed in corresponds to the
     // the one sign in manager expects.
     std::string current_email = manager->GetAuthenticatedUsername();
     const bool same_email = gaia::AreEmailsSame(current_email, email);
     if (!current_email.empty() && !same_email) {
       UMA_HISTOGRAM_ENUMERATION("Signin.Reauth",
                                 signin::HISTOGRAM_ACCOUNT_MISSMATCH,
                                 signin::HISTOGRAM_MAX);
       if (error_message) {
@@ skipping 637 matching lines @@
     }
   }
 
   RedirectToNTP(true);
   signin_tracker_.reset();
 }
 
 void OneClickSigninHelper::SigninSuccess() {
   signin_tracker_.reset();
 }