Upstream "nsurl_util.{h,mm}" from Chrome on iOS repository.

url/BUILD.gn

 # Copyright (c) 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import("//url/config.gni")
 
 # Sets the USE_ICU_ALTERNATIVES_ON_ANDROID define based on the build flag.
 config("url_icu_config") {
   if (use_icu_alternatives_on_android) {
     defines = [ "USE_ICU_ALTERNATIVES_ON_ANDROID=1" ]
@@ skipping 69 matching lines @@
     deps -= [
       "//third_party/icu:icudata",
       "//third_party/icu",
     ]
 
     sources += [
       "url_canon_icu_alternatives_android.cc",
       "url_canon_icu_alternatives_android.h",
     ]
   }
+
+  if (is_mac || is_ios) {
+    sources += [
+      "mac/url_conversions.h",
+      "mac/url_conversions.mm",
+    ]
+  }
 }
 
 # TODO(dpranke): crbug.com/360936. Get this to build and run on Android.
 if (!is_android) {
   test("url_unittests") {
     sources = [
       "gurl_unittest.cc",
       "origin_unittest.cc",
       "url_canon_icu_unittest.cc",
       "url_canon_unittest.cc",
@@ skipping 23 matching lines @@
     ]
 
     if (use_icu_alternatives_on_android) {
       sources -= [
         "url_canon_icu_unittest.cc",
       ]
       deps -= [
         "//third_party/icu:icuuc",
       ]
     }
+
+    if (is_mac || is_ios) {
+      sources += [
+        "mac/url_conversions_unittest.mm",
+      ]
+    }
   }
 }