Use in-class initializers for base::WeakPtrFactory (remaining uses on Chrome OS).

Changed NULL to nullptr where the presubmit complained (due to new line wrapping).

Generated by: https://chromium-review.googlesource.com/c/chromium/src/+/1689216

Bug: 981415
Tbr: [email protected]
Change-Id: I9c7ea90816e2a2418981108f657bc52cee8c06ef
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1703541
Commit-Queue: Jeremy Roman <[email protected]>
Reviewed-by: Jeremy Roman <[email protected]>
Reviewed-by: James Cook <[email protected]>
Reviewed-by: Gabriel Charette <[email protected]>
Cr-Original-Commit-Position: refs/heads/master@{#688514}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 47d432e71ef8ddf621b69f0fc6e6362bf1be6278
diff --git a/alarm_timer_chromeos.cc b/alarm_timer_chromeos.cc
index 787e4f5..af98c06 100644
--- a/alarm_timer_chromeos.cc
+++ b/alarm_timer_chromeos.cc
@@ -48,7 +48,7 @@
 }
 
 SimpleAlarmTimer::SimpleAlarmTimer(base::ScopedFD alarm_fd)
-    : alarm_fd_(std::move(alarm_fd)), weak_factory_(this) {}
+    : alarm_fd_(std::move(alarm_fd)) {}
 
 SimpleAlarmTimer::~SimpleAlarmTimer() {
   DCHECK(origin_task_runner_->RunsTasksInCurrentSequence());
diff --git a/alarm_timer_chromeos.h b/alarm_timer_chromeos.h
index e1301e9..c1e0012 100644
--- a/alarm_timer_chromeos.h
+++ b/alarm_timer_chromeos.h
@@ -79,7 +79,7 @@
   std::unique_ptr<base::PendingTask> pending_task_;
 
   // Used to invalidate pending callbacks.
-  base::WeakPtrFactory<SimpleAlarmTimer> weak_factory_;
+  base::WeakPtrFactory<SimpleAlarmTimer> weak_factory_{this};
 
   DISALLOW_COPY_AND_ASSIGN(SimpleAlarmTimer);
 };