DrMemory: Disable the failing SyncBackendHostTest.DownloadControlTypes test.

BUG=292960
NOTRY=true
TBR=zhaoqin@chromium.org

Review URL: https://chromiumcodereview.appspot.com/23480079

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@223444 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/gtest_exclude/unit_tests.gtest-drmemory_win32.txt

@@ -67,3 +67,6 @@ PnaclTranslationCacheTest.*
 
 # Failing on the bot. crbug.com/266972
 OneClickSigninBubbleViewTest.ShowBubble
+
+# http://crbug.com/292960
+SyncBackendHostTest.DownloadControlTypes