update setAnalysisRoots to accept package spec file

pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java

Index: pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
diff --git a/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java b/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
index e465571760b04ec3054581e6dabe44096fda5d9e..8fb6d55e9d54ac75ead22d97aae731d29b36ffa9 100644
--- a/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
+++ b/pkg/analysis_server/tool/spec/generated/java/AnalysisServer.java
@@ -174,13 +174,17 @@ public interface AnalysisServer {
    * @param included A list of the files and directories that should be analyzed.
    * @param excluded A list of the files and directories within the included directories that should
    *         not be analyzed.
-   * @param packageRoots A mapping from source directories to target directories that should override
-   *         the normal package: URI resolution mechanism. The analyzer will behave as though each
-   *         source directory in the map contains a special pubspec.yaml file which resolves any
-   *         package: URI to the corresponding path within the target directory. The effect is the
-   *         same as specifying the target directory as a "--package_root" parameter to the Dart VM
-   *         when executing any Dart file inside the source directory. Files in any directories that
-   *         are not overridden by this mapping have their package: URI's resolved using the normal
+   * @param packageRoots A mapping from source directories to package roots that should override the
+   *         normal package: URI resolution mechanism. If a package root is a directory, then the
+   *         analyzer will behave as though the associated source directory in the map contains a
+   *         special pubspec.yaml file which resolves any package: URI to the corresponding path
+   *         within that package root directory. The effect is the same as specifying the package
+   *         root directory as a "--package_root" parameter to the Dart VM when executing any Dart
+   *         file inside the source directory. If a package root is a file, then the analyzer will
+   *         behave as though that file is a ".packages" file in the source directory. The effect is
+   *         the same as specifying the file as a "--packages" parameter to the Dart VM when
+   *         executing any Dart file inside the source directory. Files in any directories that are
+   *         not overridden by this mapping have their package: URI's resolved using the normal
    *         pubspec.yaml mechanism. If this field is absent, or the empty map is specified, that
    *         indicates that the normal pubspec.yaml mechanism should always be used.
    */