Ensure guest mode browser can activate the correct window.

chrome/browser/app_controller_mac.mm

 // 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.
 
 #import "chrome/browser/app_controller_mac.h"
 
 #include "apps/app_shim/extension_app_shim_handler_mac.h"
 #include "apps/app_window_registry.h"
 #include "base/auto_reset.h"
 #include "base/bind.h"
@@ skipping 105 matching lines @@
 // global flag here, analogue to StartupBrowserCreator::InProcessStartup()
 // because otherwise the SessionService will try to restore sessions when we
 // make a new window while there are no other active windows.
 bool g_is_opening_new_window = false;
 
 // Activates a browser window having the given profile (the last one active) if
 // possible and returns a pointer to the activate |Browser| or NULL if this was
 // not possible. If the last active browser is minimized (in particular, if
 // there are only minimized windows), it will unminimize it.
 Browser* ActivateBrowser(Profile* profile) {
-  Browser* browser = chrome::FindLastActiveWithProfile(profile,
+  Browser* browser = chrome::FindLastActiveWithProfile(
+      profile->IsGuestSession() ? profile->GetOffTheRecordProfile() : profile,

[bcwhite, 2014/07/23 14:51:37]

Note that an OTRProfile is not independent but associated with a regular
profile.  You'll want to be sure that (a) FindLastActiveWithProfile() can find
an incognito browser via an OTR profile pointer and that (b) it never returns a
regular browser with the primary profile.

       chrome::HOST_DESKTOP_TYPE_NATIVE);
   if (browser)
     browser->window()->Activate();
   return browser;
 }
 
 // Creates an empty browser window with the given profile and returns a pointer
 // to the new |Browser|.
 Browser* CreateBrowser(Profile* profile) {
   {
@@ skipping 1408 matching lines @@
 
 //---------------------------------------------------------------------------
 
 namespace app_controller_mac {
 
 bool IsOpeningNewWindow() {
   return g_is_opening_new_window;
 }
 
 }  // namespace app_controller_mac