[ObjC ARC] Converts parts of ios/web/webstate to ARC.

ios/web/BUILD.gn

Index: ios/web/BUILD.gn
diff --git a/ios/web/BUILD.gn b/ios/web/BUILD.gn
index e11cb7540c7a08f8307be73a06c6db8e05e1e8c5..7749b562bca11dd7382a847d16026c40253748bf 100644
--- a/ios/web/BUILD.gn
+++ b/ios/web/BUILD.gn
@@ -203,6 +203,19 @@ source_set("web_arc") {
     "web_state/ui/crw_touch_tracking_recognizer.mm",
     "web_state/ui/crw_web_controller.h",
     "web_state/ui/crw_web_controller.mm",
+    "web_state/ui/crw_web_controller_container_view.h",
+    "web_state/ui/crw_web_controller_container_view.mm",
+    "web_state/ui/crw_web_view_content_view.mm",
+    "web_state/ui/crw_wk_script_message_router.h",
+    "web_state/ui/crw_wk_script_message_router.mm",
+    "web_state/ui/web_view_js_utils.h",
+    "web_state/ui/web_view_js_utils.mm",
+    "web_state/ui/wk_back_forward_list_item_holder.h",
+    "web_state/ui/wk_back_forward_list_item_holder.mm",
+    "web_state/ui/wk_web_view_configuration_provider.h",
+    "web_state/ui/wk_web_view_configuration_provider.mm",
+    "web_state/web_controller_observer_bridge.h",
+    "web_state/web_controller_observer_bridge.mm",
     "web_thread_impl.cc",
     "web_thread_impl.h",
     "web_view_creation_util.mm",
@@ -264,19 +277,6 @@ source_set("web") {
   ]
 
   sources = [
-    "web_state/ui/crw_web_controller_container_view.h",
-    "web_state/ui/crw_web_controller_container_view.mm",
-    "web_state/ui/crw_web_view_content_view.mm",
-    "web_state/ui/crw_wk_script_message_router.h",
-    "web_state/ui/crw_wk_script_message_router.mm",
-    "web_state/ui/web_view_js_utils.h",
-    "web_state/ui/web_view_js_utils.mm",
-    "web_state/ui/wk_back_forward_list_item_holder.h",
-    "web_state/ui/wk_back_forward_list_item_holder.mm",
-    "web_state/ui/wk_web_view_configuration_provider.h",
-    "web_state/ui/wk_web_view_configuration_provider.mm",
-    "web_state/web_controller_observer_bridge.h",
-    "web_state/web_controller_observer_bridge.mm",
     "web_state/web_state.mm",
     "web_state/web_state_delegate.mm",
     "web_state/web_state_delegate_bridge.mm",