Support piping log data over the service protocol

sdk/lib/_internal/js_runtime/lib/developer_patch.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // Patch file for dart:developer library.
 
 import 'dart:_js_helper' show patch;
 import 'dart:_foreign_helper' show JS;
 
 /// If [when] is true, stop the program as if a breakpoint where hit at the
@@ skipping 12 matching lines @@
   }
   return when;
 }
 
 /// Send a reference to [object] to any attached debuggers so they may open an
 /// inspector on the object. Returns the argument.
 @patch
 inspect(object) {
   return object;
 }
+
+@patch
+/// Emit a log event.
+/// [sequenceNumber] is a monotonically increasing sequence number.
+/// [millisececondsSinceEpoch] is a timestamp.
+/// [level] is the severity level (value between 0 and 2000 inclusive).
+/// [name] is the name of the source of the log message.
+/// [message] is the log message.
+/// [zone] (optional) the zone where the log was emitted
+/// [error] (optional) an error object associated with this log event.
+/// [stackTrace] (optional) a stack trace associated with this log event.
+log(int sequenceNumber,
+    int millisecondsSinceEpoch,
+    int level,
+    String name,
+    String message,
+    [Zone zone,
+     Object error,
+     StackTrace stackTrace]) {
+  // TODO.
+}