Move ui_test_utils::RunMessageLoop to test_utils so that it can be reused by content_browsertests.

chrome/browser/sync/test/integration/bookmarks_helper.cc

Index: chrome/browser/sync/test/integration/bookmarks_helper.cc
===================================================================
--- chrome/browser/sync/test/integration/bookmarks_helper.cc	(revision 148497)
+++ chrome/browser/sync/test/integration/bookmarks_helper.cc	(working copy)
@@ -42,12 +42,12 @@
   }
   void WaitForGetFavicon() {
     wait_for_load_ = true;
-    ui_test_utils::RunMessageLoop();
+    content::RunMessageLoop();
     ASSERT_TRUE(node_->is_favicon_loaded());
   }
   void WaitForSetFavicon() {
     wait_for_load_ = false;
-    ui_test_utils::RunMessageLoop();
+    content::RunMessageLoop();
   }
   virtual void Loaded(BookmarkModel* model, bool ids_reassigned) OVERRIDE {}
   virtual void BookmarkNodeMoved(BookmarkModel* model,