Add support for completion of case labels.

pkg/analysis_server/lib/src/services/completion/optype.dart

Index: pkg/analysis_server/lib/src/services/completion/optype.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/optype.dart b/pkg/analysis_server/lib/src/services/completion/optype.dart
index c4d0cfec7b2f4a133c7600e40dc67de0df02b314..ef2902bc63ca2e76bb71523df82c819643447cf6 100644
--- a/pkg/analysis_server/lib/src/services/completion/optype.dart
+++ b/pkg/analysis_server/lib/src/services/completion/optype.dart
@@ -42,6 +42,11 @@ class OpType {
   bool includeStatementLabelSuggestions = false;
 
   /**
+   * Indicates whether case labels should be suggested.
+   */
+  bool includeCaseLabelSuggestions = false;
+
+  /**
    * Determine the suggestions that should be made based upon the given
    * [CompletionTarget] and [offset].
    */
@@ -206,6 +211,7 @@ class _OpTypeAstVisitor extends GeneralizingAstVisitor {
   void visitContinueStatement(ContinueStatement node) {
     if (node.label == null || identical(entity, node.label)) {
       optype.includeStatementLabelSuggestions = true;
+      optype.includeCaseLabelSuggestions = true;
     }
   }