[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 17 matching lines @@
 #include "base/threading/thread.h"
 #include "base/time/tick_clock.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/media/webrtc/media_capture_devices_dispatcher.h"
 #include "chrome/browser/media/webrtc/media_stream_capture_indicator.h"
 #include "chrome/browser/memory/oom_memory_details.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/resource_coordinator/tab_manager_observer.h"
 #include "chrome/browser/resource_coordinator/tab_manager_web_contents_data.h"
+#include "chrome/browser/sessions/tab_loader.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/tab_contents/tab_contents_iterator.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
 #include "chrome/browser/ui/tabs/tab_utils.h"
 #include "chrome/common/chrome_constants.h"
 #include "chrome/common/chrome_features.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/url_constants.h"
@@ skipping 70 matching lines @@
   std::vector<gfx::Rect> bounds_list_;
 
   DISALLOW_COPY_AND_ASSIGN(BoundsList);
 };
 
 }  // namespace
 
 ////////////////////////////////////////////////////////////////////////////////
 // TabManager
 
+class TabManager::TabManagerSessionRestoreObserver
+    : public SessionRestoreObserver {
+ public:
+  explicit TabManagerSessionRestoreObserver(TabManager* tab_manager)
+      : tab_manager_(tab_manager) {
+    SessionRestoreObserver::AddObserver(this);
+  }
+
+  ~TabManagerSessionRestoreObserver() {
+    SessionRestoreObserver::RemoveObserver(this);
+  }
+
+  // SessionRestoreObserver implementation:
+  void OnTabLoadingStarted() override {
+    tab_manager_->OnSessionRestoreTabLoadingStarted();
+  }
+
+  void OnTabLoadingEnded() override {
+    tab_manager_->OnSessionRestoreTabLoadingEnded();
+  }
+
+ private:
+  TabManager* tab_manager_;
+};
+
 constexpr base::TimeDelta TabManager::kDefaultMinTimeToPurge;
 
 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),
+      is_in_session_restore_tab_loading_(false),
       weak_ptr_factory_(this) {
 #if defined(OS_CHROMEOS)
   delegate_.reset(new TabManagerDelegate(weak_ptr_factory_.GetWeakPtr()));
 #endif
   browser_tab_strip_tracker_.Init();
+  session_restore_observer_.reset(new TabManagerSessionRestoreObserver(this));
 }
 
 TabManager::~TabManager() {
   Stop();
 }
 
 void TabManager::Start() {
 #if defined(OS_WIN) || defined(OS_MACOSX)
   // Note that discarding is now enabled by default. This check is kept as a
   // kill switch.
@@ skipping 314 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::OnSessionRestoreTabLoadingStarted() {
+  DCHECK(!is_in_session_restore_tab_loading_);
+  is_in_session_restore_tab_loading_ = true;
+}
+
+void TabManager::OnSessionRestoreTabLoadingEnded() {
+  DCHECK(is_in_session_restore_tab_loading_);
+  is_in_session_restore_tab_loading_ = 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