[iOS] Upstream web_controller_provider_impl.{h,mm}.

ios/chrome/browser/web/BUILD.gn

 # Copyright 2016 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.
 
 source_set("web") {
   sources = [
     "dom_altering_lock.h",
     "dom_altering_lock.mm",
     "resubmit_data_controller.h",
     "resubmit_data_controller.mm",
   ]
   deps = [
     "//base",
     "//components/strings",
     "//ios/web",
     "//ui/base",
   ]
+  public_deps = [
+    ":web_arc",
+  ]
 }
+
+source_set("web_arc") {
+  visibility = [ ":web" ]
+  sources = [
+    "web_controller_provider_factory_impl.h",
+    "web_controller_provider_factory_impl.mm",
+    "web_controller_provider_impl.h",
+    "web_controller_provider_impl.mm",
+  ]
+  deps = [
+    "//base",
+    "//ios/public/provider/web",
+    "//ios/web",
+    "//url",
+  ]
+  configs += [ "//build/config/compiler:enable_arc" ]
+}