[Session restore] Add MRU logic to loading of background pages.

content/browser/web_contents/web_contents_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 "content/browser/web_contents/web_contents_impl.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/lazy_instance.h"
@@ skipping 1034 matching lines @@
   }
 
   if (delegate_)
     delegate_->NavigationStateChanged(this, changed_flags);
 }
 
 base::TimeTicks WebContentsImpl::GetLastActiveTime() const {
   return last_active_time_;
 }
 
+void WebContentsImpl::SetLastActiveTime(base::TimeTicks last_active_time) {
+  last_active_time_ = last_active_time;
+}
+
 void WebContentsImpl::WasShown() {
   controller_.SetActive(true);
 
   for (RenderWidgetHostView* view : GetRenderWidgetHostViewsInTree()) {
     if (view) {
       view->Show();
 #if defined(OS_MACOSX)
       view->SetActive(true);
 #endif
     }
@@ skipping 3324 matching lines @@
   player_map->erase(it);
 }
 
 void WebContentsImpl::SetForceDisableOverscrollContent(bool force_disable) {
   force_disable_overscroll_content_ = force_disable;
   if (view_)
     view_->SetOverscrollControllerEnabled(CanOverscrollContent());
 }
 
 }  // namespace content