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

chrome/browser/sessions/session_restore_delegate.h

 // Copyright 2015 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.
 
 #ifndef CHROME_BROWSER_SESSIONS_SESSION_RESTORE_DELEGATE_H_
 #define CHROME_BROWSER_SESSIONS_SESSION_RESTORE_DELEGATE_H_
 
 #include <vector>
 
 #include "base/time/time.h"
 
 namespace content {
 class WebContents;
 }
 
 // SessionRestoreDelegate is responsible for creating the tab loader and the
 // stats collector.
 class SessionRestoreDelegate {
  public:
   struct RestoredTab {
     content::WebContents* contents;
     bool is_active;
   };
 
   static void RestoreTabs(const std::vector<RestoredTab>& tabs,
-                          const base::TimeTicks& restore_started);
+                          const base::TimeTicks& restore_started,
+                          bool active_only);
 
  private:
   DISALLOW_IMPLICIT_CONSTRUCTORS(SessionRestoreDelegate);
 };
 
 #endif  // CHROME_BROWSER_SESSIONS_SESSION_RESTORE_DELEGATE_H_