Convert Pass()→std::move() for iOS build.

net/disk_cache/blockfile/file_ios.cc

Index: net/disk_cache/blockfile/file_ios.cc
diff --git a/net/disk_cache/blockfile/file_ios.cc b/net/disk_cache/blockfile/file_ios.cc
index d1d1919f1dd71979f06ee5ef7ce573bde826bd2d..b2a6d6ef4006bffe0a033395d9da788d6686d6f9 100644
--- a/net/disk_cache/blockfile/file_ios.cc
+++ b/net/disk_cache/blockfile/file_ios.cc
@@ -8,6 +8,7 @@
 #include <stdint.h>
 
 #include <limits>
+#include <utility>
 
 #include "base/bind.h"
 #include "base/location.h"
@@ -173,10 +174,7 @@ void DeleteFileInFlightIO() {
 namespace disk_cache {
 
 File::File(base::File file)
-    : init_(true),
-      mixed_(true),
-      base_file_(file.Pass()) {
-}
+    : init_(true), mixed_(true), base_file_(std::move(file)) {}
 
 bool File::Init(const base::FilePath& name) {
   if (base_file_.IsValid())