[ARC] Converts part of ios/web/public to ARC.

ios/web/BUILD.gn

Index: ios/web/BUILD.gn
diff --git a/ios/web/BUILD.gn b/ios/web/BUILD.gn
index 80bff5f48fdd3dced8497e3fef5ded64e26a1625..44d5c17989ee112950cc846ae3971d62adca5ba8 100644
--- a/ios/web/BUILD.gn
+++ b/ios/web/BUILD.gn
@@ -119,6 +119,21 @@ source_set("web_arc") {
     "public/ssl_status.cc",
     "public/ssl_status.h",
     "public/string_util.h",
+    "public/url_data_source_ios.h",
+    "public/url_scheme_util.h",
+    "public/url_schemes.h",
+    "public/url_schemes.mm",
+    "public/url_util.h",
+    "public/web_capabilities.cc",
+    "public/web_capabilities.h",
+    "public/web_client.h",
+    "public/web_client.mm",
+    "public/web_kit_constants.h",
+    "public/web_state/context_menu_params.h",
+    "public/web_state/credential.h",
+    "public/web_state/crw_web_controller_observer.h",
+    "public/web_state/crw_web_user_interface_delegate.h",
+    "public/web_state/crw_web_view_proxy.h",
     "string_util.cc",
     "url_scheme_util.mm",
     "url_util.cc",
@@ -184,21 +199,6 @@ source_set("web") {
   ]
 
   sources = [
-    "public/url_data_source_ios.h",
-    "public/url_scheme_util.h",
-    "public/url_schemes.h",
-    "public/url_schemes.mm",
-    "public/url_util.h",
-    "public/web_capabilities.cc",
-    "public/web_capabilities.h",
-    "public/web_client.h",
-    "public/web_client.mm",
-    "public/web_kit_constants.h",
-    "public/web_state/context_menu_params.h",
-    "public/web_state/credential.h",
-    "public/web_state/crw_web_controller_observer.h",
-    "public/web_state/crw_web_user_interface_delegate.h",
-    "public/web_state/crw_web_view_proxy.h",
     "public/web_state/crw_web_view_scroll_view_proxy.h",
     "public/web_state/global_web_state_observer.h",
     "public/web_state/js/credential_util.h",