Use multi-profile mount point by default after browser crash and in Guest session.

chrome/browser/chromeos/profiles/profile_helper.cc

 // Copyright (c) 2013 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/chromeos/profiles/profile_helper.h"
 
 #include "base/callback.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/browsing_data/browsing_data_helper.h"
@@ skipping 100 matching lines @@
       !UserManager::Get()->IsLoggedInAsStub()) {
     chromeos::OAuth2LoginManager* login_manager =
         chromeos::OAuth2LoginManagerFactory::GetInstance()->GetForProfile(
             profile);
     if (login_manager)
       login_manager->AddObserver(this);
   }
 }
 
 base::FilePath ProfileHelper::GetActiveUserProfileDir() {
-  DCHECK(!active_user_id_hash_.empty());
-  return base::FilePath(chrome::kProfileDirPrefix + active_user_id_hash_);
+  return GetUserProfileDir(active_user_id_hash_);
+}
+
+base::FilePath ProfileHelper::GetUserProfileDir(
+    const std::string& user_id_hash) {
+  DCHECK(!user_id_hash.empty());
+  return base::FilePath(chrome::kProfileDirPrefix + user_id_hash);
 }
 
 void ProfileHelper::Initialize() {
   UserManager::Get()->AddSessionStateObserver(this);
 }
 
 void ProfileHelper::ClearSigninProfile(const base::Closure& on_clear_callback) {
   on_clear_callbacks_.push_back(on_clear_callback);
   if (signin_profile_clear_requested_)
     return;
@@ skipping 42 matching lines @@
 ////////////////////////////////////////////////////////////////////////////////
 // ProfileHelper, UserManager::UserSessionStateObserver implementation:
 
 void ProfileHelper::ActiveUserHashChanged(const std::string& hash) {
   active_user_id_hash_ = hash;
   base::FilePath profile_path = GetProfilePathByUserIdHash(hash);
   LOG(INFO) << "Switching to profile path: " << profile_path.value();
 }
 
 }  // namespace chromeos