[ObjC ARC] Converts ios/web:web to ARC.

ios/web/web_state/ui/web_view_js_utils.mm

Index: ios/web/web_state/ui/web_view_js_utils.mm
diff --git a/ios/web/web_state/ui/web_view_js_utils.mm b/ios/web/web_state/ui/web_view_js_utils.mm
index 1afe2d8a9ba9d9cbe6f6463aa4df09fa90d931a6..6bdca3bbceaef1ee18faa5c4734e158c3356ed66 100644
--- a/ios/web/web_state/ui/web_view_js_utils.mm
+++ b/ios/web/web_state/ui/web_view_js_utils.mm
@@ -9,11 +9,14 @@
 
 #include "base/logging.h"
 #include "base/mac/foundation_util.h"
-#import "base/mac/scoped_nsobject.h"
 #include "base/memory/ptr_util.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/values.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace {
 
 // Converts result of WKWebView script evaluation to base::Value, parsing
@@ -30,7 +33,8 @@ std::unique_ptr<base::Value> ValueResultFromWKResult(id wk_result,
     return result;
   }
 
-  CFTypeID result_type = CFGetTypeID(wk_result);
+  CFTypeRef typeRef = (__bridge CFTypeRef)wk_result;
+  CFTypeID result_type = CFGetTypeID(typeRef);
   if (result_type == CFStringGetTypeID()) {
     result.reset(new base::Value(base::SysNSStringToUTF16(wk_result)));
     DCHECK(result->IsType(base::Value::Type::STRING));
@@ -91,10 +95,10 @@ void ExecuteJavaScript(WKWebView* web_view,
     dispatch_async(dispatch_get_main_queue(), ^{
       NSString* error_message =
           @"JS evaluation failed because there is no web view.";
-      base::scoped_nsobject<NSError> error([[NSError alloc]
+      NSError* error = [[NSError alloc]
           initWithDomain:kJSEvaluationErrorDomain
                     code:JS_EVALUATION_ERROR_CODE_NO_WEB_VIEW
-                userInfo:@{NSLocalizedDescriptionKey : error_message}]);
+                userInfo:@{NSLocalizedDescriptionKey : error_message}];
       completion_handler(nil, error);
     });
     return;