Suppress data race in ExtensioNGCMAppHandlerTest

BUG=386385
TBR=jianli@chromium.org
NOTRY=true

Review URL: https://codereview.chromium.org/344633003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@278264 0039d316-1c4b-4281-b951-d872f2087c98

base/debug/tsan_suppressions.cc

@@ -293,6 +293,9 @@ char kTSanDefaultSuppressions[] =
 // http://crbug.com/380554
 "deadlock:g_type_add_interface_static\n"
 
+// http:://crbug.com/386385
+"race:appcache::AppCacheStorageImpl::DatabaseTask::CallRunCompleted\n"
+
 // End of suppressions.
 ;  // Please keep this semicolon.