--- chrome/browser/browser_process.h
+++ chrome/browser/browser_process.h
@@ -92,7 +92,7 @@ class BrowserProcess {
   // database. History has its own thread since it has much higher traffic.
   virtual base::Thread* db_thread() = 0;
 
-#if defined(OS_LINUX)
+#if defined(USE_X11)
   // Returns the thread that is used to process UI requests in cases where
   // we can't route the request to the UI thread. Note that this thread
   // should only be used by the IO thread and this method is only safe to call
diff --git chrome/browser/browser_process_impl.cc chrome/browser/browser_process_impl.cc
index 05d4299..c553174 100644