Various fixes for sync socket implementation.

sdk/lib/_internal/js_runtime/lib/io_patch.dart

Index: sdk/lib/_internal/js_runtime/lib/io_patch.dart
diff --git a/sdk/lib/_internal/js_runtime/lib/io_patch.dart b/sdk/lib/_internal/js_runtime/lib/io_patch.dart
index e7ed5bef5c6f5f5f6c1b6c8a63e64745b1a69c0b..e3342f108f3f83fe1ae57bd81a5e12bad37e9fae 100644
--- a/sdk/lib/_internal/js_runtime/lib/io_patch.dart
+++ b/sdk/lib/_internal/js_runtime/lib/io_patch.dart
@@ -428,6 +428,14 @@ class SecureSocket {
 }
 
 @patch
+class RawSynchronousSocket {
+  @patch
+  static RawSynchronousSocket connectSync(host, int port) {
+    throw new UnsupportedError("RawSynchronousSocket.connectSync");
+  }
+}
+
+@patch
 class SecurityContext {
   @patch
   factory SecurityContext() {