Add KeepAliveStateObserver, add the Restart option

chrome/browser/background/background_mode_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/background/background_mode_manager.h"
 
 #include <stddef.h>
 #include <algorithm>
 #include <string>
 #include <utility>
@@ skipping 293 matching lines @@
         base::Bind(&BackgroundModeManager::OnBackgroundModeEnabledPrefChanged,
                    base::Unretained(this)));
   }
 
   // Keep the browser alive until extensions are done loading - this is needed
   // by the --no-startup-window flag. We want to stay alive until we load
   // extensions, at which point we should either run in background mode (if
   // there are background apps) or exit if there are none.
   if (command_line.HasSwitch(switches::kNoStartupWindow)) {
     keep_alive_for_startup_.reset(
-        new ScopedKeepAlive(keep_alive::Origin::BACKGROUND_MODE_MANAGER));
+        new ScopedKeepAlive(keep_alive::Origin::BACKGROUND_MODE_MANAGER_STARTUP,

[Bernhard Bauer, 2016/02/24 16:54:33]

Are we ever going to use the same origin with different restart options? If not,
it seems kind of strange to centralize origins themselves but keep the restart
options at the call sites. Maybe something to bring up  with Scott over on the
other CL?

[dgn, 2016/02/24 19:08:32]

Up to callers to decide what to do with their origins I guess? My interpretation
is that since we don't have strings to declare and risk typos, spreading enums
is less of an issue. So in a sense it's more consistent with the changes Scott
had me make.

+                            keep_alive::RestartOption::DISABLED));
   } else {
     // Otherwise, start with background mode suspended in case we're launching
     // in a mode that doesn't open a browser window. It will be resumed when the
     // first browser window is opened.
     SuspendBackgroundMode();
   }
 
   // If the -keep-alive-for-test flag is passed, then always keep chrome running
   // in the background until the user explicitly terminates it.
   if (command_line.HasSwitch(switches::kKeepAliveForTest))
@@ skipping 433 matching lines @@
   UpdateKeepAliveAndTrayIcon();
 }
 
 void BackgroundModeManager::ResumeBackgroundMode() {
   background_mode_suspended_ = false;
   UpdateKeepAliveAndTrayIcon();
 }
 
 void BackgroundModeManager::UpdateKeepAliveAndTrayIcon() {
   if (in_background_mode_ && !background_mode_suspended_) {
-    if (!keep_alive_) {
+    if (!keep_alive_)

[Bernhard Bauer, 2016/02/24 16:54:33]

Keep the braces, as the body is more than one line.

       keep_alive_.reset(
-          new ScopedKeepAlive(keep_alive::Origin::BACKGROUND_MODE_MANAGER));
-    }
+          new ScopedKeepAlive(keep_alive::Origin::BACKGROUND_MODE_MANAGER,
+                              keep_alive::RestartOption::ENABLED));
     CreateStatusTrayIcon();
     return;
   }
 
   RemoveStatusTrayIcon();
   keep_alive_.reset();
 }
 
 void BackgroundModeManager::OnBrowserAdded(Browser* browser) {
   ResumeBackgroundMode();
@@ skipping 245 matching lines @@
     }
   }
   return profile_it;
 }
 
 bool BackgroundModeManager::IsBackgroundModePrefEnabled() const {
   PrefService* service = g_browser_process->local_state();
   DCHECK(service);
   return service->GetBoolean(prefs::kBackgroundModeEnabled);
 }