Move RunAllPendingInMessageLoop from ui_test_utils.h to test_utils.h, so that it can be reused by c…

chrome/browser/download/download_browsertest.cc

Index: chrome/browser/download/download_browsertest.cc
===================================================================
--- chrome/browser/download/download_browsertest.cc	(revision 149002)
+++ chrome/browser/download/download_browsertest.cc	(working copy)
@@ -681,8 +681,8 @@
     }
 
     // Wait till the |DownloadFile|s are destroyed.
-    ui_test_utils::RunAllPendingInMessageLoop(content::BrowserThread::FILE);
-    ui_test_utils::RunAllPendingInMessageLoop(content::BrowserThread::UI);
+    content::RunAllPendingInMessageLoop(content::BrowserThread::FILE);
+    content::RunAllPendingInMessageLoop(content::BrowserThread::UI);
 
     // Validate that the correct files were downloaded.
     download_items.clear();