Remove support for String operator + from dart2js.

dart/lib/isolate/frog/messages.dart

Index: dart/lib/isolate/frog/messages.dart
diff --git a/dart/lib/isolate/frog/messages.dart b/dart/lib/isolate/frog/messages.dart
index e1f7a5120951355e579e1dcc27d834617006d8da..595db85d017dd8cac1f7067f1111c58be94241d5 100644
--- a/dart/lib/isolate/frog/messages.dart
+++ b/dart/lib/isolate/frog/messages.dart
@@ -150,8 +150,9 @@ class _Copier extends _MessageTraverser {
       return _visitNativeOrWorkerPort(port._port);
     } else {
       // TODO(floitsch): Use real exception (which one?).
-      throw "internal error: must call _waitForPendingPorts to ensure all"
-          + " ports are resolved at this point.";
+      throw

[Lasse Reichstein Nielsen, 2012/06/18 09:25:32]

I liked the original indentation better. Just remove the '+' but keep the
indentation.
It tricks an old JS programmer to see a newline between "throw" and it's operand
- that's not allowed in JS.

[ahe, 2012/06/18 10:39:16]

I don't follow the logic of your argument.

+          "internal error: must call _waitForPendingPorts to ensure all"
+          " ports are resolved at this point.";
     }
   }
 }
@@ -201,8 +202,9 @@ class _Serializer extends _MessageTraverser {
       return _visitNativeOrWorkerPort(port._port);
     } else {
       // TODO(floitsch): Use real exception (which one?).
-      throw "internal error: must call _waitForPendingPorts to ensure all"
-          + " ports are resolved at this point.";
+      throw
+          "internal error: must call _waitForPendingPorts to ensure all"
+          " ports are resolved at this point.";

[Lasse Reichstein Nielsen, 2012/06/18 09:25:32]

Ditto.

[ahe, 2012/06/18 10:39:16]

Ditto.

     }
   }