Attempting to resolve a race condition with PowerMonitor

net/url_request/url_request_job.cc

Index: net/url_request/url_request_job.cc
diff --git a/net/url_request/url_request_job.cc b/net/url_request/url_request_job.cc
index 78f704a3a15f54f612c96ba4f4313be633198e19..a3348c69cf8fa684de3290b7f8e5d0d725ec2a7a 100644
--- a/net/url_request/url_request_job.cc
+++ b/net/url_request/url_request_job.cc
@@ -36,9 +36,7 @@ URLRequestJob::URLRequestJob(URLRequest* request,
       deferred_redirect_status_code_(-1),
       network_delegate_(network_delegate),
       weak_factory_(this) {
-  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
-  if (power_monitor)
-    power_monitor->AddObserver(this);
+  base::PowerMonitor::AddObserverThreadSafe(this);
 }
 
 void URLRequestJob::SetUpload(UploadDataStream* upload) {
@@ -243,9 +241,7 @@ void URLRequestJob::NotifyURLRequestDestroyed() {
 }
 
 URLRequestJob::~URLRequestJob() {
-  base::PowerMonitor* power_monitor = base::PowerMonitor::Get();
-  if (power_monitor)
-    power_monitor->RemoveObserver(this);
+  base::PowerMonitor::RemoveObserverThreadSafe(this);
 }
 
 void URLRequestJob::NotifyCertificateRequested(