[Win] Add a fast profile switcher to the Windows taskbar item.

chrome/browser/ui/startup/startup_browser_creator.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/startup/startup_browser_creator.h"
 
 #include <algorithm>   // For max().
 #include <set>
 
 #include "apps/app_load_service.h"
@@ skipping 728 matching lines @@
 
   // The profile isn't loaded yet and so needs to be loaded asynchronously.
   if (!profile) {
     profile_manager->CreateProfileAsync(profile_path,
         base::Bind(&StartupBrowserCreator::ProcessCommandLineOnProfileCreated,
                    command_line, cur_dir), base::string16(), base::string16(),
                    std::string());
     return;
   }
 
+  if (command_line.HasSwitch(switches::kActivateExistingProfileBrowser)) {

[tapted, 2014/11/04 23:10:48]

nit: perhaps comment here, something like "If the profile is loaded, it might
also have an existing browser to activate when using the taskbar-activated
profile switcher. In this case, skip regular command line processing, since that
will open a new tab."

[noms (inactive), 2014/11/10 21:46:08]

Done.

+    Browser* browser = chrome::FindTabbedBrowser(
+        profile, false, chrome::HOST_DESKTOP_TYPE_NATIVE);
+    if (browser) {
+      browser->window()->Activate();
+      return;
+    }
+  }
+
   ProcessCmdLineImpl(command_line, cur_dir, false, profile, Profiles(), NULL,
                      NULL);
 }
 
 // static
 bool StartupBrowserCreator::ActivatedProfile() {
   return profile_launch_observer.Get().activated_profile();
 }
 
 bool HasPendingUncleanExit(Profile* profile) {
@@ skipping 11 matching lines @@
   // If we are showing the app list then chrome isn't shown so load the app
   // list's profile rather than chrome's.
   if (command_line.HasSwitch(switches::kShowAppList)) {
     return AppListService::Get(chrome::HOST_DESKTOP_TYPE_NATIVE)->
         GetProfilePath(user_data_dir);
   }
 
   return g_browser_process->profile_manager()->GetLastUsedProfileDir(
       user_data_dir);
 }