Get rid of most std::vector<int>::iterator usage.

Most std::vector iteration can just be range-based For loops.

TBR=zea@chromium.org

Change-Id: Ibe18f8a088a27f41dbe0e38c40787bbcef28a7e2
Reviewed-on: https://chromium-review.googlesource.com/741545
Reviewed-by: Lei Zhang <thestig@chromium.org>
Reviewed-by: Robert Sesek <rsesek@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: Stanislav Chiknavaryan <stanisc@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#513080}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 0fe3176e177a0ec556a0b3956fd0bd8e1cb147bf
diff --git a/linux/syscall_broker/broker_host.cc b/linux/syscall_broker/broker_host.cc
index 6e1dacc..6c216cf 100644
--- a/linux/syscall_broker/broker_host.cc
+++ b/linux/syscall_broker/broker_host.cc
@@ -147,10 +147,8 @@
       reply_ipc, write_pickle.data(), write_pickle.size(), opened_files);
 
   // Close anything we have opened in this process.
-  for (std::vector<int>::iterator it = opened_files.begin();
-       it != opened_files.end();
-       ++it) {
-    int ret = IGNORE_EINTR(close(*it));
+  for (int fd : opened_files) {
+    int ret = IGNORE_EINTR(close(fd));
     DCHECK(!ret) << "Could not close file descriptor";
   }