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

chrome/browser/resource_coordinator/tab_manager.h

 // 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.
 
 #ifndef CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_MANAGER_H_
 #define CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_MANAGER_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 144 matching lines @@
 
   // Returns a unique ID for a WebContents. Do not cast back to a pointer, as
   // the WebContents could be deleted if the user closed the tab.
   static int64_t IdFromWebContents(content::WebContents* web_contents);
 
   // Return whether tabs are being loaded during session restore.
   bool IsSessionRestoreLoadingTabs() const {
     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);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ShouldPurgeAtDefaultTime);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, DefaultTimeToPurgeInCorrectRange);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, AutoDiscardable);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, CanOnlyDiscardOnce);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, ChildProcessNotifications);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, Comparator);
   FRIEND_TEST_ALL_PREFIXES(TabManagerTest, DiscardedTabKeepsLastActiveTime);
@@ skipping 215 matching lines @@
   std::vector<BrowserInfo> test_browser_info_list_;
 
   // List of observers that will receive notifications on state changes.
   base::ObserverList<TabManagerObserver> observers_;
 
   bool is_session_restore_loading_tabs_;
 
   class TabManagerSessionRestoreObserver;
   std::unique_ptr<TabManagerSessionRestoreObserver> session_restore_observer_;
 
+  // Whether the user has switched from the initial foreground tab or not.
+  bool initial_session_restore_foreground_tab_changed_;
+
   // Weak pointer factory used for posting delayed tasks.
   base::WeakPtrFactory<TabManager> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(TabManager);
 };
 
 }  // namespace resource_coordinator
 
 #endif  // CHROME_BROWSER_RESOURCE_COORDINATOR_TAB_MANAGER_H_