Also disable HistoryWebUITest.multipleSelect on Mac due to flakeness.

BUG=375910
TBR=zea@chromium.org

Review URL: https://codereview.chromium.org/295333004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@272773 0039d316-1c4b-4281-b951-d872f2087c98

chrome/test/data/webui/history_browsertest.js

@@ -506,9 +506,9 @@ TEST_F('HistoryWebUITest', 'DISABLED_bulkDeletion', function() {
 
 /**
  * Test selecting multiple entries using shift click.
- * Disabled due to time out on win: crbug/375910
+ * Disabled due to time out on win and mac: crbug/375910
  */
-GEN('#if defined(OS_WIN)');
+GEN('#if defined(OS_WIN) || defined(OS_MACOSX)');
 GEN('#define MAYBE_multipleSelect DISABLED_multipleSelect');
 GEN('#else');
 GEN('#define MAYBE_multipleSelect multipleSelect');