[Tab Metrics] Measure FP, FCP and FMP for Foreground Tab during Session Restore

chrome/browser/resource_coordinator/tab_manager.h

Index: chrome/browser/resource_coordinator/tab_manager.h
diff --git a/chrome/browser/resource_coordinator/tab_manager.h b/chrome/browser/resource_coordinator/tab_manager.h
index 3a0e3b0d08ddfeffd0c9911d90c06e6aa42ff47f..123a50a6d516d763f716f46a3bb9b86cdad792da 100644
--- a/chrome/browser/resource_coordinator/tab_manager.h
+++ b/chrome/browser/resource_coordinator/tab_manager.h
@@ -190,6 +190,10 @@ class TabManager : public TabStripModelObserver,
     return is_session_restore_loading_tabs_;
   }
 
+  bool HasSessionRestoreInitialForegroundTabChanged() const {
+    return initial_session_restore_foreground_tab_changed_;
+  }
+
  private:
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, PurgeBackgroundRenderer);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ActivateTabResetPurgeState);
@@ -465,6 +469,9 @@ class TabManager : public TabStripModelObserver,
   class TabManagerSessionRestoreObserver;
   std::unique_ptr<TabManagerSessionRestoreObserver> session_restore_observer_;
 
+  // True if the initial foreground tab is switched away.
+  bool initial_session_restore_foreground_tab_changed_;
+
   // The list of navigations that are delayed.
   std::vector<BackgroundTabNavigationThrottle*> pending_navigations_;