[TabMetrics] Add signals that mark the start and end of session restore.

chrome/browser/resource_coordinator/tab_manager.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 "chrome/browser/resource_coordinator/tab_manager.h"
 
 #include <stddef.h>
 
 #include <algorithm>
 #include <set>
@@ skipping 118 matching lines @@
 
 TabManager::TabManager()
     : discard_count_(0),
       recent_tab_discard_(false),
       discard_once_(false),
 #if !defined(OS_CHROMEOS)
       minimum_protection_time_(base::TimeDelta::FromMinutes(10)),
 #endif
       browser_tab_strip_tracker_(this, nullptr, nullptr),
       test_tick_clock_(nullptr),
+      in_session_restore_(false),
       weak_ptr_factory_(this) {
 #if defined(OS_CHROMEOS)
   delegate_.reset(new TabManagerDelegate(weak_ptr_factory_.GetWeakPtr()));
 #endif
   browser_tab_strip_tracker_.Init();
 }
 
 TabManager::~TabManager() {
   Stop();
 }
@@ skipping 319 matching lines @@
 
   // Being more recently active is more important.
   return first.last_active > second.last_active;
 }
 
 // static
 int64_t TabManager::IdFromWebContents(WebContents* web_contents) {
   return reinterpret_cast<int64_t>(web_contents);
 }
 
+void TabManager::OnSessionRestoreStarted() {
+  DCHECK(!in_session_restore_);
+  in_session_restore_ = true;
+}
+
+void TabManager::OnSessionRestoreEnded() {
+  DCHECK(in_session_restore_);
+  in_session_restore_ = false;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // TabManager, private:
 
 void TabManager::OnDiscardedStateChange(content::WebContents* contents,
                                         bool is_discarded) {
   for (TabManagerObserver& observer : observers_)
     observer.OnDiscardedStateChange(contents, is_discarded);
 }
 
 void TabManager::OnAutoDiscardableStateChange(content::WebContents* contents,
@@ skipping 409 matching lines @@
     browser_info.window_is_minimized = browser->window()->IsMinimized();
     browser_info.window_bounds = browser->window()->GetBounds();
     browser_info.browser_is_app = browser->is_app();
     browser_info_list.push_back(browser_info);
   }
 
   return browser_info_list;
 }
 
 }  // namespace resource_coordinator