Allow Chromium's DBus service ownership to be stealable

chrome/browser/chromeos/dbus/cros_dbus_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/chromeos/dbus/cros_dbus_service.h"
 
 #include "base/bind.h"
 #include "base/chromeos/chromeos_version.h"
 #include "base/stl_util.h"
 #include "base/threading/platform_thread.h"
@@ skipping 31 matching lines @@
   // Starts the D-Bus service.
   void Start() {
     // Make sure we're running on the origin thread (i.e. the UI thread in
     // production).
     DCHECK(OnOriginThread());
 
     // Return if the service has been already started.
     if (service_started_)
       return;
 
+    // There are some situations, described in http://crbug.com/234382#c27,
+    // where processes on Linux can wind up stuck in an uninterruptible state
+    // for tens of seconds. If this happens when Chrome is trying to exit,
+    // this unkillable process can wind up clinging to ownership of
+    // kLibCrosServiceName while the system is trying to restart the browser.
+    // This leads to a fatal situation if we don't allow the new browser
+    // instance to replace the old as the owner of kLibCrosServiceName as seen
+    // in http://crbug.com/234382. Hence, REQUIRE_PRIMARY_ALLOW_REPLACEMENT.
     bus_->RequestOwnership(kLibCrosServiceName,
+                           dbus::Bus::REQUIRE_PRIMARY_ALLOW_REPLACEMENT,
                            base::Bind(&CrosDBusServiceImpl::OnOwnership,
                                       base::Unretained(this)));
 
     exported_object_ = bus_->GetExportedObject(
         dbus::ObjectPath(kLibCrosServicePath));
 
     for (size_t i = 0; i < service_providers_.size(); ++i)
       service_providers_[i]->Start(exported_object_);
 
     service_started_ = true;
@@ skipping 82 matching lines @@
   VLOG(1) << "CrosDBusService Shutdown completed";
 }
 
 CrosDBusService::~CrosDBusService() {
 }
 
 CrosDBusService::ServiceProviderInterface::~ServiceProviderInterface() {
 }
 
 }  // namespace chromeos