Add BackgroundModeOptimizer that can restart the browser

chrome/browser/lifetime/keep_alive_registry.cc

 // Copyright 2016 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/lifetime/keep_alive_registry.h"
 
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/lifetime/application_lifetime.h"
 #include "chrome/browser/lifetime/keep_alive_state_observer.h"
 #include "chrome/browser/lifetime/keep_alive_types.h"
@@ skipping 74 matching lines @@
   DCHECK_GE(registered_keep_alives_[origin], 0);
   if (new_count == 0)
     registered_keep_alives_.erase(origin);
 
   if (restart == KeepAliveRestartOption::ENABLED)
     --restart_allowed_count_;
 
   bool new_keeping_alive = IsKeepingAlive();
   bool new_restart_allowed = IsRestartAllowed();
 
+  // Update the KeepAlive state first, so that listeners can check if we are
+  // trying to shutdown.
+  if (new_keeping_alive != old_keeping_alive)
+    OnKeepAliveStateChanged(new_keeping_alive);
+
   if (new_restart_allowed != old_restart_allowed)
     OnRestartAllowedChanged(new_restart_allowed);
 
-  if (new_keeping_alive != old_keeping_alive)
-    OnKeepAliveStateChanged(new_keeping_alive);
-
   DVLOG(1) << "New state of the KeepAliveRegistry:" << *this;
 }
 
 void KeepAliveRegistry::OnKeepAliveStateChanged(bool new_keeping_alive) {
   DVLOG(1) << "Notifying KeepAliveStateObservers: KeepingAlive changed to: "
            << new_keeping_alive;
   FOR_EACH_OBSERVER(KeepAliveStateObserver, observers_,
                     OnKeepAliveStateChanged(new_keeping_alive));
 }
 
@@ skipping 10 matching lines @@
       << ", KeepAlives=[";
   for (auto counts_per_origin_it : registry.registered_keep_alives_) {
     if (counts_per_origin_it != *registry.registered_keep_alives_.begin())
       out << ", ";
     out << counts_per_origin_it.first << " (" << counts_per_origin_it.second
         << ")";
   }
   out << "]}";
   return out;
 }