net: move IsLocalhost() function into url_util.h

This patch moves the last function in net_util.h into url_util.h. We are
moving it there because it also operates on a URL part (host).

BUG=488531
TEST=net_unittests --gtest_filter=UrlUtilTest.IsLocalhost
[email protected]
[email protected]

Review URL: https://codereview.chromium.org/1726693002

Cr-Commit-Position: refs/heads/master@{#377115}
diff --git a/net/url_request/url_request_throttler_manager.cc b/net/url_request/url_request_throttler_manager.cc
index 3f08e9e1..a36f0c9 100644
--- a/net/url_request/url_request_throttler_manager.cc
+++ b/net/url_request/url_request_throttler_manager.cc
@@ -6,7 +6,7 @@
 
 #include "base/logging.h"
 #include "base/strings/string_util.h"
-#include "net/base/net_util.h"
+#include "net/base/url_util.h"
 #include "net/log/net_log.h"
 
 namespace net {