Additional clean-up after moving to the new task model; a breaking change needed to allow a bug to …

pkg/analyzer/CHANGELOG.md

+## 0.27.0
+* Support for DEP 37 (Assert with optional message).
+* Lexical support for DEP 40 (Interface libraries). This does not include any semantic checking to ensure that the
+  implementation libraries are compatible with the interface library.
+* Cleaned up the initialization of plugins. Clients are now required to initialize plugins, possibly using the utility
+  method AnalysisEngine.processRequiredPlugins().
+* Removed the old task model and code that supported it. None of the removed code was intended to be public API, but
+  might be in use anyway.
+
 ## 0.26.3
 * (Internal) Support for `_embedder.yaml` discovery and processing.
 
 ## 0.26.2
 * Add code generation utilities for use in both analyzer and analysis server.
 
 ## 0.26.1+17
 * (Internal) Introduced context configuration logic (`configureContext()` extracted from server).
 
 ## 0.26.1+16
@@ skipping 70 matching lines @@
 * Requires Dart SDK 1.12-dev or greater
 * Enable null-aware operators (DEP 9) by default.
 * Generic method support in the element model.
 
 ## 0.25.2-alpha.1
 
 * `dart:sdk` extension `.sdkext` changed to `_sdkext` (to play nicer with pub).
 
 ## 0.25.2-alpha.0
 
-* Initial support for analyzing `dart:sdk` extensions from `.sdkext`. 
+* Initial support for analyzing `dart:sdk` extensions from `.sdkext`.
 
 ## 0.25.1
 
 * (Internal) code reorganization to address analysis warnings due to SDK reorg.
 * First steps towards `.packages` support.
 
 ## 0.25.0
 
 * Commandline interface moved to dedicated `analyzer_cli` package. Files moved:
   * `bin/analyzer.dart`
   * `lib/options.dart`
   * `lib/src/analyzer_impl.dart`
   * `lib/src/error_formatter.dart`
 * Removed dependency on the `args` package.
 
 ## 0.22.1
 
 * Changes in the async/await support.
 
 
 ## 0.22.0
 
   New API:
-  
+
 * `Source.uri` added.
 
   Breaking changes:
 
 * `DartSdk.fromEncoding` replaced with `fromFileUri`.
 * `Source.resolveRelative` replaced with `resolveRelativeUri`.