Changing SessionService to have a BaseSessionService, not being one.

chrome/browser/sessions/base_session_service_delegate_impl.cc

 // Copyright 2014 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/sessions/base_session_service_delegate_impl.h"
 
 #include "chrome/common/url_constants.h"
 #include "content/public/browser/browser_thread.h"
 #include "url/gurl.h"
 
 BaseSessionServiceDelegateImpl::BaseSessionServiceDelegateImpl(
     bool should_use_delayed_save)
       : should_use_delayed_save_(should_use_delayed_save) {}
 
 base::SequencedWorkerPool* BaseSessionServiceDelegateImpl::GetBlockingPool() {
   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
   return content::BrowserThread::GetBlockingPool();
 }
 
 bool BaseSessionServiceDelegateImpl::ShouldTrackEntry(const GURL& url) {
   // Blacklist chrome://quit and chrome://restart to avoid quit or restart
   // loops.
-  return !(url.SchemeIs(content::kChromeUIScheme) &&
+  return url.is_valid() &&
+         !(url.SchemeIs(content::kChromeUIScheme) &&
           (url.host() == chrome::kChromeUIQuitHost ||
            url.host() == chrome::kChromeUIRestartHost));
 }
 
 bool BaseSessionServiceDelegateImpl::ShouldUseDelayedSave() {
   return should_use_delayed_save_;
 }