Remove string + uses from dart:html.

lib/html/src/SVGElementWrappingImplementation.dart

Index: lib/html/src/SVGElementWrappingImplementation.dart
diff --git a/lib/html/src/SVGElementWrappingImplementation.dart b/lib/html/src/SVGElementWrappingImplementation.dart
index f9f321b729a59c6cff69894e75d5f2e03db9aa91..04ab4c460b66c9a336f9a36cb4d7dff4f49c58cf 100644
--- a/lib/html/src/SVGElementWrappingImplementation.dart
+++ b/lib/html/src/SVGElementWrappingImplementation.dart
@@ -1,4 +1,4 @@
-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
+// Copyright (c) 2012, 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.
 
@@ -31,7 +31,8 @@ class SVGElementWrappingImplementation extends ElementWrappingImplementation imp
     parentTag.innerHTML = svg;
     if (parentTag.elements.length == 1) return parentTag.nodes.removeLast();
 
-    throw new IllegalArgumentException('SVG had ${parentTag.elements.length} ' +
+    throw new IllegalArgumentException(
+        'SVG had ${parentTag.elements.length} '
         'top-level elements but 1 expected');
   }