base: Use std::move() instead of Pass() for real movable types.

base/prefs/pref_member.cc

Index: base/prefs/pref_member.cc
diff --git a/base/prefs/pref_member.cc b/base/prefs/pref_member.cc
index 64c3d6a99348b7f12f56372de56f061a6e7b0027..934237d37ca9df1ba474799721e6dfe7a582f78b 100644
--- a/base/prefs/pref_member.cc
+++ b/base/prefs/pref_member.cc
@@ -4,6 +4,8 @@
 
 #include "base/prefs/pref_member.h"
 
+#include <utility>
+
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/location.h"
@@ -56,7 +58,7 @@ void PrefMemberBase::MoveToThread(
   // Load the value from preferences if it hasn't been loaded so far.
   if (!internal())
     UpdateValueFromPref(base::Closure());
-  internal()->MoveToThread(task_runner.Pass());
+  internal()->MoveToThread(std::move(task_runner));
 }
 
 void PrefMemberBase::OnPreferenceChanged(PrefService* service,
@@ -124,7 +126,7 @@ void PrefMemberBase::Internal::UpdateValue(
 void PrefMemberBase::Internal::MoveToThread(
     scoped_refptr<SingleThreadTaskRunner> task_runner) {
   CheckOnCorrectThread();
-  thread_task_runner_ = task_runner.Pass();
+  thread_task_runner_ = std::move(task_runner);
 }
 
 bool PrefMemberVectorStringUpdate(const base::Value& value,