[ObjC ARC] Converts ios/chrome/test/app:test_support to ARC.

ios/chrome/test/app/static_html_view_test_util.mm

Index: ios/chrome/test/app/static_html_view_test_util.mm
diff --git a/ios/chrome/test/app/static_html_view_test_util.mm b/ios/chrome/test/app/static_html_view_test_util.mm
index 9daa7a0daeb907af6ea1442c03a46203a0e66a70..07d2347b651b9deecceeff9444bb1e51dce8010f 100644
--- a/ios/chrome/test/app/static_html_view_test_util.mm
+++ b/ios/chrome/test/app/static_html_view_test_util.mm
@@ -12,6 +12,10 @@
 #import "ios/chrome/test/app/chrome_test_util.h"
 #import "ios/testing/wait_util.h"
 
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
 namespace chrome_test_util {
 
 // Synchronously returns the result of executed JavaScript.
@@ -31,7 +35,7 @@ id ExecuteScriptInStaticController(
     return did_finish;
   });
 
-  return [result autorelease];
+  return result;
 }
 
 // Returns the StaticHtmlViewController for the given |web_state|. If none is