Add regex escaping code to Mac sandbox implementation and re-enable the utility process on OS X.

chrome/browser/web_resource/web_resource_service.cc

Index: chrome/browser/web_resource/web_resource_service.cc
diff --git a/chrome/browser/web_resource/web_resource_service.cc b/chrome/browser/web_resource/web_resource_service.cc
index c4ffa4791a0e073ff435ba7aecd53a06d6e7f534..3d213f1981bbb9e4aeb8987985d5e031d9103565 100644
--- a/chrome/browser/web_resource/web_resource_service.cc
+++ b/chrome/browser/web_resource/web_resource_service.cc
@@ -111,9 +111,8 @@ class WebResourceService::UnpackerClient
         web_resource_service_->resource_dispatcher_host_ != NULL &&
         !CommandLine::ForCurrentProcess()->HasSwitch(switches::kSingleProcess);
 
-#if defined(OS_POSIX)
-    // TODO(port): Don't use a utility process on linux (crbug.com/22703) or
-    // MacOS (crbug.com/8102) until problems related to autoupdate are fixed.
+#if defined(OS_LINUX)
+    // TODO(port): Don't use a utility process on linux (crbug.com/22703).
     use_utility_process = false;
 #endif