[Session restore] Expose lazy mode and fix browser tests.

chrome/browser/sessions/better_session_restore_browsertest.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 "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/files/file_util.h"
 #include "base/lazy_instance.h"
 #include "base/path_service.h"
 #include "base/prefs/pref_service.h"
@@ skipping 196 matching lines @@
 
   void CheckReloadedPageRestored() {
     CheckTitle(browser(), title_pass_);
   }
 
   void CheckReloadedPageRestored(Browser* browser) {
     CheckTitle(browser, title_pass_);
   }
 
   void CheckReloadedPageNotRestored() {
+    // If only active tabs are loaded, force loading of the tab.
+    if (SessionRestore::IsLoadingActiveTabsOnly()) {
+      content::WebContents* web_contents =
+          browser()->tab_strip_model()->GetWebContentsAt(0);

[sky, 2015/04/16 15:40:10]

Is there only ever one webcontents that isn't loading? Seems better to invoke
LoadIfNecessary on all webcontents.

[Georges Khalil, 2015/04/16 18:10:18]

Yes, this only has one page. If calls CheckTitle which waits
for the title of that single page to change (line 230).

That being said, the change was simple to loop the webcontents
and makes the code more futureproof.

Done.

+      web_contents->GetController().LoadIfNecessary();
+    }
     CheckReloadedPageNotRestored(browser());
   }
 
   void CheckReloadedPageNotRestored(Browser* browser) {
     CheckTitle(browser, title_storing_);
   }
 
   void CheckTitle(Browser* browser, const base::string16& expected_title) {
     content::WebContents* web_contents =
         browser->tab_strip_model()->GetWebContentsAt(0);
@@ skipping 608 matching lines @@
   CookieSettings::Factory::GetForProfile(new_browser->profile())->
       SetDefaultCookieSetting(CONTENT_SETTING_SESSION_ONLY);
   // ... even if background mode is active.
   EnableBackgroundMode();
   new_browser = QuitBrowserAndRestore(new_browser, true);
   StoreDataWithPage(new_browser, "cookies.html");
   DisableBackgroundMode();
   new_browser = QuitBrowserAndRestore(new_browser, true);
   StoreDataWithPage(new_browser, "cookies.html");
 }