Excluding test failing with 'impossible happened' error

TBR=glider@chromium.org
BUG=51716
TEST=none

Review URL: http://codereview.chromium.org/7765004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@98481 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/gtest_exclude/ui_tests.gtest_mac.txt

@@ -175,6 +175,7 @@ WorkerFileSystemTest.FileFromFileEntrySync
 WorkerFileSystemTest.FileWriterSyncTruncateExtend
 WorkerFileSystemTest.FileWriterTruncateExtend
 WorkerFileSystemTest.Temporary
+PrintPreviewUITest.AdvancedPrintCommandEnabled
 
 # Valgrind dies on bszB assertion, see http://crbug.com/58145
 AutomatedUITestBase.Home