Disable Places Sync on some frequent random failing test, to workaround bug 507790 and reduce orangeness. a=tests-only

toolkit/components/places/tests/queries/head_queries.js

@@ -567,6 +567,8 @@ function flush_main_thread_events()
 // flushes are active, so we turn off syncing for them.
 let randomFailingSyncTests = [
   "test_results-as-visit.js",
+  "test_sorting.js",
+  "test_redirectsMode.js",
 ];
 let currentTestFilename = do_get_file(_TEST_FILE[0], true).leafName;
 if (randomFailingSyncTests.indexOf(currentTestFilename) != -1) {

toolkit/components/places/tests/unit/head_bookmarks.js

@@ -305,6 +305,8 @@ let randomFailingSyncTests = [
   "test_removeVisitsByTimeframe.js",
   "test_tagging.js",
   "test_utils_getURLsForContainerNode.js",
+  "test_exclude_livemarks.js",
+  "test_402799.js",
 ];
 let currentTestFilename = do_get_file(_TEST_FILE[0], true).leafName;
 if (randomFailingSyncTests.indexOf(currentTestFilename) != -1) {