CHANGELOG entry for CssClassSet

CHANGELOG.md

 ## 1.11.0
 
 ### Core library changes
 
 * Update experimental Isolate API:
   - Make priorty parameters of `Isolate.ping` and `Isolate.kill` methods
     a named parameter.
   - Remove the `Isolate.AS_EVENT` priority.
   - Add extra `response` parameter to `Isolate.ping` and
     `Isolate.addOnExitListener`.
   [r45092](https://code.google.com/p/dart/source/detail?r=45092),
 
 ## 1.10.0
 
 ### Core library changes
 
 * Fix behavior of `HtmlEscape` in `dart:convert`. No longer escape
   no-break space (U+00A0) anywhere or forward slash ('/', U+002F) in element
   context. Slash is still escaped in the "unknown" context.
   [r45003](https://code.google.com/p/dart/source/detail?r=45003),
   [r45153](https://code.google.com/p/dart/source/detail?r=45153),
   [r45189](https://code.google.com/p/dart/source/detail?r=45189)
 
+* dart:html: CssClassSet method arguments must now be 'tokens', i.e. non-empty
+  strings with no white-space characters. The implementation was incorrect for
+  class names containing spaces. The fix is to forbid spaces and provide a
+  faster implementation.
+  [r44898](https://code.google.com/p/dart/source/detail?r=44898),
+  [r45307](https://code.google.com/p/dart/source/detail?r=45307)
+
 ## 1.9.3 (2015-04-14)
 
 This is a bug fix release which merges a number of commits from `bleeding_edge`.
 
 * dart2js: Addresses as issue with minified Javascript output with CSP enabled -
   [r44453](https://code.google.com/p/dart/source/detail?r=44453)
 
 * Editor: Fixes accidental updating of files in the pub cache during rename
   refactoring - [r44677](https://code.google.com/p/dart/source/detail?r=44677)
 
@@ skipping 219 matching lines @@
     they will keep the Dart process alive until they time out. This fixes the
     handling of persistent connections. Previously, the client would shut down
     immediately after a request.
 
   * **Breaking change:** `HttpServer` no longer compresses all traffic by
     default. The new `autoCompress` property can be set to `true` to re-enable
     compression.
 
 * `dart:isolate`: `Isolate.spawnUri` added the optional `packageRoot` argument,
   which controls how it resolves `package:` URIs.