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

chrome/browser/resource_coordinator/tab_manager.cc

Index: chrome/browser/resource_coordinator/tab_manager.cc
diff --git a/chrome/browser/resource_coordinator/tab_manager.cc b/chrome/browser/resource_coordinator/tab_manager.cc
index 9ce446cfd721ac2a23a6c8128224e1b70016d080..e7097dc88ca4edf0c5852f9b4ca51079f7baa607 100644
--- a/chrome/browser/resource_coordinator/tab_manager.cc
+++ b/chrome/browser/resource_coordinator/tab_manager.cc
@@ -35,6 +35,7 @@
 #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"
@@ -136,6 +137,8 @@ TabManager::TabManager()
 #endif
       browser_tab_strip_tracker_(this, nullptr, nullptr),
       test_tick_clock_(nullptr),
+      in_session_restore_tab_loading_(false),

[lpy, 2017/06/23 22:35:57]

is_in_session_restore_tab_loading_

[ducbui, 2017/06/23 23:30:14]

Done.

+      session_restore_observer_instance_(this),
       weak_ptr_factory_(this) {
 #if defined(OS_CHROMEOS)
   delegate_.reset(new TabManagerDelegate(weak_ptr_factory_.GetWeakPtr()));
@@ -475,6 +478,16 @@ int64_t TabManager::IdFromWebContents(WebContents* web_contents) {
   return reinterpret_cast<int64_t>(web_contents);
 }
 
+void TabManager::OnSessionRestoreTabLoadingStarted() {
+  DCHECK(!in_session_restore_tab_loading_);
+  in_session_restore_tab_loading_ = true;
+}
+
+void TabManager::OnSessionRestoreTabLoadingEnded() {
+  DCHECK(in_session_restore_tab_loading_);
+  in_session_restore_tab_loading_ = false;
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 // TabManager, private:
 
@@ -903,4 +916,23 @@ std::vector<TabManager::BrowserInfo> TabManager::GetBrowserInfoList() const {
   return browser_info_list;
 }
 
+TabManager::SessionRestoreObserverInstance::SessionRestoreObserverInstance(
+    TabManager* tab_manager)
+    : tab_manager_(tab_manager) {
+  SessionRestoreObserver::AddObserver(this);
+}
+
+TabManager::SessionRestoreObserverInstance::~SessionRestoreObserverInstance() {
+  SessionRestoreObserver::RemoveObserver(this);
+}
+
+// SessionRestoreObserver implementation:
+void TabManager::SessionRestoreObserverInstance::OnTabLoadingStarted() {
+  tab_manager_->OnSessionRestoreTabLoadingStarted();
+}
+
+void TabManager::SessionRestoreObserverInstance::OnTabLoadingEnded() {
+  tab_manager_->OnSessionRestoreTabLoadingEnded();
+}
+
 }  // namespace resource_coordinator