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

chrome/browser/sessions/session_service.cc

Index: chrome/browser/sessions/session_service.cc
diff --git a/chrome/browser/sessions/session_service.cc b/chrome/browser/sessions/session_service.cc
index 99de7204e61bdf7d52e078b0e979d175b29f58eb..0b8759a2792ac60d3c11138ff3d9033927f6c7df 100644
--- a/chrome/browser/sessions/session_service.cc
+++ b/chrome/browser/sessions/session_service.cc
@@ -487,6 +487,16 @@ void SessionService::SetTabExtensionAppID(
                       tab_id, extension_app_id).Pass());
 }
 
+void SessionService::SetLastActiveTime(const SessionID& window_id,
+                                       const SessionID& tab_id,
+                                       base::TimeTicks last_active_time) {
+  if (!ShouldTrackChangesToWindow(window_id))
+    return;
+
+  ScheduleCommand(
+      sessions::CreateLastActiveTimeCommand(tab_id, last_active_time).Pass());
+}
+
 base::CancelableTaskTracker::TaskId SessionService::GetLastSession(
     const SessionCallback& callback,
     base::CancelableTaskTracker* tracker) {
@@ -727,6 +737,13 @@ void SessionService::BuildCommandsForTab(const SessionID& window_id,
         sessions::CreatePinnedStateCommand(session_id, true));
   }
 
+  if (SessionRestore::GetSmartRestoreMode() ==
+      SessionRestore::SMART_RESTORE_MODE_MRU) {
+    base_session_service_->AppendRebuildCommand(
+        sessions::CreateLastActiveTimeCommand(session_id,
+                                              tab->GetLastActiveTime()));
+  }
+
   extensions::TabHelper* extensions_tab_helper =
       extensions::TabHelper::FromWebContents(tab);
   if (extensions_tab_helper->extension_app()) {