[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 1cee43c9dadf642ea523d32de3eb0989e587ff99..022b2f46d66b013d2b53e0c12c6aef61f0d8165c 100644
--- a/chrome/browser/resource_coordinator/tab_manager.h
+++ b/chrome/browser/resource_coordinator/tab_manager.h
@@ -198,6 +198,10 @@ 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);
@@ -495,6 +499,9 @@ 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_;
+
   // When the timer fires, it forces loading the next background tab if needed.
   std::unique_ptr<base::OneShotTimer> force_load_timer_;