Access to Chrome via the System Tray should go through the User Manager.

chrome/browser/ui/cocoa/profiles/user_manager_mac.mm

 // Copyright 2014 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/cocoa/profiles/user_manager_mac.h"
 
 #include "chrome/app/chrome_command_ids.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/profiles/profile_manager.h"
 #include "chrome/browser/ui/browser_dialogs.h"
 #import "chrome/browser/ui/cocoa/browser_window_utils.h"
 #include "chrome/browser/ui/cocoa/chrome_event_processing_window.h"
 #include "chrome/grit/chromium_strings.h"
 #include "content/public/browser/native_web_keyboard_event.h"
 #include "content/public/browser/web_contents.h"
 #include "content/public/browser/web_contents_delegate.h"
 #include "ui/base/l10n/l10n_util_mac.h"
 
 // Default window size. Taken from the views implementation in
 // chrome/browser/ui/views/user_manager_view.cc.
 // TODO(noms): Figure out if this size can be computed dynamically or adjusted
 // for smaller screens.
 const int kWindowWidth = 900;
 const int kWindowHeight = 700;
 
-namespace chrome {
-
-// Declared in browser_dialogs.h so others don't have to depend on this header.
-void ShowUserManager(const base::FilePath& profile_path_to_focus) {
-  UserManagerMac::Show(
-      profile_path_to_focus, profiles::USER_MANAGER_NO_TUTORIAL);
+void UserManager::Show(
+    const base::FilePath& profile_path_to_focus,
+    profiles::UserManagerTutorialMode tutorial_mode,
+    profiles::UserManagerProfileSelected profile_open_action) {
+  UserManagerMac::Show(profile_path_to_focus,
+                        tutorial_mode,
+                        profile_open_action);
 }
 
-void ShowUserManagerWithTutorial(profiles::UserManagerTutorialMode tutorial) {
-  UserManagerMac::Show(base::FilePath(), tutorial);
-}
-
-void HideUserManager() {
+void UserManager::Hide() {
   UserManagerMac::Hide();
 }
 
-}  // namespace chrome
+bool UserManager::IsShowing() {
+  return UserManagerMac::IsShowing();
+}
 
 // Custom WebContentsDelegate that allows handling of hotkeys.
 class UserManagerWebContentsDelegate : public content::WebContentsDelegate {
  public:
   UserManagerWebContentsDelegate(ChromeEventProcessingWindow* window)
     : window_(window) {}
 
   // WebContentsDelegate implementation. Forwards all unhandled keyboard events
   // to the current window.
   virtual void HandleKeyboardEvent(
@@ skipping 115 matching lines @@
 
 UserManagerMac::UserManagerMac(Profile* profile) {
   window_controller_.reset([[UserManagerWindowController alloc]
       initWithProfile:profile withObserver:this]);
 }
 
 UserManagerMac::~UserManagerMac() {
 }
 
 // static
-void UserManagerMac::Show(const base::FilePath& profile_path_to_focus,
-                          profiles::UserManagerTutorialMode tutorial_mode) {
+void UserManagerMac::Show(
+    const base::FilePath& profile_path_to_focus,
+    profiles::UserManagerTutorialMode tutorial_mode,
+    profiles::UserManagerProfileSelected profile_open_action) {
   if (instance_) {
     // If there's a user manager window open already, just activate it.
     [instance_->window_controller_ show];
     return;
   }
 
   // Create the guest profile, if necessary, and open the User Manager
   // from the guest profile.
   profiles::CreateGuestProfileForUserManager(
       profile_path_to_focus,
       tutorial_mode,
+      profile_open_action,
       base::Bind(&UserManagerMac::OnGuestProfileCreated));
 }
 
 // static
 void UserManagerMac::Hide() {
   if (instance_)
     [instance_->window_controller_ close];
 }
 
 // static
 bool UserManagerMac::IsShowing() {
   return instance_ ? [instance_->window_controller_ isVisible]: false;
 }
 
 // static
 void UserManagerMac::OnGuestProfileCreated(Profile* guest_profile,
                                            const std::string& url) {
   instance_ = new UserManagerMac(guest_profile);
   [instance_->window_controller_ showURL:GURL(url)];
 }
 
 void UserManagerMac::WindowWasClosed() {
   instance_ = NULL;
   delete this;
 }