Remove the SHA1 implementation used by web sockets and use the dart:crypto library one instead.

runtime/vm/unit_test.cc

Index: runtime/vm/unit_test.cc
diff --git a/runtime/vm/unit_test.cc b/runtime/vm/unit_test.cc
index 65174d02e22560a4a779af6d2d49e733bcc1cc9e..4a382dae862b12a58271357d638c5fbc3bde7406 100644
--- a/runtime/vm/unit_test.cc
+++ b/runtime/vm/unit_test.cc
@@ -83,6 +83,8 @@ static Dart_Handle LibraryTagHandler(Dart_LibraryTag tag,
       return Builtin::LoadLibrary(Builtin::kUriLibrary);
     } else if (DartUtils::IsDartUtfLibURL(url_chars)) {
       return Builtin::LoadLibrary(Builtin::kUtfLibrary);
+    } else if (DartUtils::IsDartCryptoLibURL(url_chars)) {
+      return Builtin::LoadLibrary(Builtin::kCryptoLibrary);
     } else {
       return Dart_Error("Do not know how to load '%s'", url_chars);
     }