Chrome OS should open to empty desktop when session restore is empty.

chrome/browser/ui/startup/startup_browser_creator_impl.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_impl.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
@@ skipping 323 matching lines @@
   }
 
   // Open the required browser windows and tabs. First, see if
   // we're being run as an application window. If so, the user
   // opened an app shortcut.  Don't restore tabs or open initial
   // URLs in that case. The user should see the window as an app,
   // not as chrome.
   // Special case is when app switches are passed but we do want to restore
   // session. In that case open app window + focus it after session is restored.
   content::WebContents* app_contents = NULL;
-  if (OpenApplicationWindow(profile, &app_contents) &&
-      !browser_defaults::kAppRestoreSession) {
+  if (OpenApplicationWindow(profile, &app_contents)) {
     RecordLaunchModeHistogram(LM_AS_WEBAPP);
   } else {
     RecordLaunchModeHistogram(urls_to_open.empty() ?
                               LM_TO_BE_DECIDED : LM_WITH_URLS);
 
     // Notify user if the Preferences backup is invalid or changes to settings
     // affecting browser startup have been detected.
     CheckPreferencesBackup(profile);
 
-    // Watch for |app_contents| closing since ProcessLaunchURLs might run a
-    // synchronous session restore which has a nested message loop and could
-    // close |app_contents|.
-    WebContentsCloseObserver app_contents_observer;
-    if (browser_defaults::kAppRestoreSession && app_contents)
-      app_contents_observer.SetContents(app_contents);
-
     ProcessLaunchURLs(process_startup, urls_to_open);
 
     // If this is an app launch, but we didn't open an app window, it may
     // be an app tab.
     OpenApplicationTab(profile);
 
-    // In case of app mode + session restore we want to focus that app.
-    if (app_contents_observer.contents())
-      app_contents_observer.contents()->GetView()->SetInitialFocus();
-
     if (process_startup) {
       if (browser_defaults::kOSSupportsOtherBrowsers &&
           !command_line_.HasSwitch(switches::kNoDefaultBrowserCheck)) {
         // Generally, the default browser prompt should not be shown on first
         // run. However, when the set-as-default dialog has been suppressed, we
         // need to allow it.
         if ((!is_first_run_ ||
              (browser_creator_ &&
               browser_creator_->is_default_browser_dialog_suppressed())) &&
             !chrome::ShowAutolaunchPrompt(profile)) {
@@ skipping 226 matching lines @@
     if (!profile_->DidLastSessionExitCleanly() &&
         !command_line_.HasSwitch(switches::kRestoreLastSession)) {
       // The last session crashed. It's possible automatically loading the
       // page will trigger another crash, locking the user out of chrome.
       // To avoid this, don't restore on startup but instead show the crashed
       // infobar.
       VLOG(1) << "Unclean exit; not processing";
       return false;
     }
 
-    uint32 restore_behavior = SessionRestore::SYNCHRONOUS |
-                              SessionRestore::ALWAYS_CREATE_TABBED_BROWSER;
+    uint32 restore_behavior = SessionRestore::SYNCHRONOUS;
+    if (browser_defaults::kAlwaysCreateTabbedBrowserOnSessionRestore ||
+        CommandLine::ForCurrentProcess()->HasSwitch(
+            switches::kCreateBrowserOnStartupForTests)) {

[sky, 2012/09/12 15:07:20]

I suspect this doesn't compile since the switch is only defined on chromeos.
Make the switch defined every where.

[Nikita (slow), 2012/09/12 15:13:32]

Done.

+      restore_behavior |= SessionRestore::ALWAYS_CREATE_TABBED_BROWSER;
+    }
+
 #if defined(OS_MACOSX)
     // On Mac, when restoring a session with no windows, suppress the creation
     // of a new window in the case where the system is launching Chrome via a
     // login item or Lion's resume feature.
     if (base::mac::WasLaunchedAsLoginOrResumeItem()) {
       restore_behavior = restore_behavior &
                          ~SessionRestore::ALWAYS_CREATE_TABBED_BROWSER;
     }
 #endif
 
@@ skipping 317 matching lines @@
         // New:
         prefs->GetString(prefs::kHomePage),
         prefs->GetBoolean(prefs::kHomePageIsNewTabPage),
         prefs->GetBoolean(prefs::kShowHomeButton),
         // Backup:
         backup_homepage,
         backup_homepage_is_ntp,
         backup_show_home_button));
   }
 }