Add union types to the analysis server API spec.

editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/AnalysisServer.java

Index: editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/AnalysisServer.java
diff --git a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/AnalysisServer.java b/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/AnalysisServer.java
index 544bfb0b0f53c9c15966a2fef378e8b08ec12426..e50a0f0bf3ce37ee5df5a8be5f71a29c8de046ce 100644
--- a/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/AnalysisServer.java
+++ b/editor/tools/plugins/com.google.dart.server/src/com/google/dart/server/AnalysisServer.java
@@ -162,8 +162,7 @@ public interface AnalysisServer {
    * path to a directory on the filesystem.
    *
    * @param files A table mapping the files whose content has changed to a description of the content
-   *         change. Each value should be one of the following types: AddContentOverlay,
-   *         ChangeContentOverlay, or RemoveContentOverlay.
+   *         change.
    */
   public void analysis_updateContent(Map<String, Object> files);