Clear session-only data when all browser windows are closed.

chrome/browser/sessions/session_service.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/sessions/session_service.h"
 
 #include <algorithm>
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/pickle.h"
 #include "base/threading/thread.h"
+#include "chrome/browser/background/background_mode_manager.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/chrome_notification_types.h"
 #include "chrome/browser/extensions/tab_helper.h"
 #include "chrome/browser/prefs/session_startup_pref.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/sessions/session_backend.h"
 #include "chrome/browser/sessions/session_command.h"
+#include "chrome/browser/sessions/session_data_deleter.h"
 #include "chrome/browser/sessions/session_restore.h"
 #include "chrome/browser/sessions/session_tab_helper.h"
 #include "chrome/browser/sessions/session_types.h"
 #include "chrome/browser/ui/browser_iterator.h"
 #include "chrome/browser/ui/browser_list.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
 #include "chrome/browser/ui/host_desktop.h"
 #include "chrome/browser/ui/startup/startup_browser_creator.h"
 #include "chrome/browser/ui/tabs/tab_strip_model.h"
@@ skipping 296 matching lines @@
     ScheduleCommand(CreateWindowClosedCommand(window_id.id()));
   } else if (pending_window_close_ids_.find(window_id.id()) ==
              pending_window_close_ids_.end()) {
     // We'll hit this if user closed the last tab in a window.
     has_open_trackable_browsers_ = HasOpenTrackableBrowsers(window_id);
     if (should_record_close_as_pending())
       pending_window_close_ids_.insert(window_id.id());
     else
       ScheduleCommand(CreateWindowClosedCommand(window_id.id()));
   }
+#if !defined(OS_MACOSX) && !defined(OS_CHROMEOS)

[marja, 2013/10/16 14:18:08]

Why not for mac and chromeos? Because of some "how sessions should look like"
differences? Because for mac and chromeos, chrome keeps running even though
windows are closed? (Maybe add a comment; this looks familiar but I cannot
exactly remember what this was about.)

[Sam McNally, 2013/10/16 23:30:59]

Correct. Switched to kBrowserAliveWithNoWindows and added a comment.

+  if (!has_open_trackable_browsers_ &&
+      !g_browser_process->background_mode_manager()->IsBackgroundModeActive()) {
+    DeleteSessionOnlyData(profile());
+  }
+#endif
 }
 
 void SessionService::SetWindowType(const SessionID& window_id,
                                    Browser::Type type,
                                    AppType app_type) {
   if (!should_track_changes_for_browser_type(type, app_type))
     return;
 
   windows_tracking_.insert(window_id.id());
 
@@ skipping 1404 matching lines @@
       contents->GetController().GetDefaultSessionStorageNamespace();
   session_storage_namespace->SetShouldPersist(false);
   SessionTabHelper* session_tab_helper =
       SessionTabHelper::FromWebContents(contents);
   TabClosed(session_tab_helper->window_id(),
             session_tab_helper->session_id(),
             contents->GetClosedByUserGesture());
   RecordSessionUpdateHistogramData(content::NOTIFICATION_WEB_CONTENTS_DESTROYED,
                                    &last_updated_tab_closed_time_);
 }