Mark failing test - we exposed a V8 bug.

tests/lib/lib.status

Index: tests/lib/lib.status
diff --git a/tests/lib/lib.status b/tests/lib/lib.status
index 26e406b2c03faaa56f43334894c81f1d9fa09875..097a374e5917abc37041af3a91c0ab1651b019ab 100644
--- a/tests/lib/lib.status
+++ b/tests/lib/lib.status
@@ -25,6 +25,9 @@ async/run_async4_test: Pass, Fail # no global exception handler in isolates. htt
 [ $compiler == dart2js && $checked ]
 async/stream_event_transform_test: Fail # Issue 7733.
 
+[ $compiler == dart2js && $unchecked && ($runtime == d8 || $runtime == chrome || $runtime == drt) ]
+crypto/sha1_test: Fail # V8 bug: https://code.google.com/p/v8/issues/detail?id=2692
+
 [ $compiler == dart2js && $jscl ]
 async/future_test: Fail # Timer interface not supported; dartbug.com/7728.
 async/slow_consumer2_test: Fail # Timer interface not supported; dartbug.com/7728.