extract field formal contributor from prefixed element contributor

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

Index: pkg/analysis_server/lib/src/services/completion/prefixed_element_contributor.dart
diff --git a/pkg/analysis_server/lib/src/services/completion/prefixed_element_contributor.dart b/pkg/analysis_server/lib/src/services/completion/prefixed_element_contributor.dart
index 5a52da8f134d8c03e108567d3e21e9f410d3908f..b6fe585de589e2f41ffafc4016540fccd674bc2d 100644
--- a/pkg/analysis_server/lib/src/services/completion/prefixed_element_contributor.dart
+++ b/pkg/analysis_server/lib/src/services/completion/prefixed_element_contributor.dart
@@ -96,73 +96,6 @@ class _ExpressionSuggestionBuilder implements SuggestionBuilder {
 }
 
 /**
- * A suggestion builder for 'this.' constructor arguments.
- */
-class _FieldFormalSuggestionBuilder implements SuggestionBuilder {
-  final DartCompletionRequest request;
-
-  _FieldFormalSuggestionBuilder(this.request);
-
-  @override
-  bool computeFast(AstNode node) {
-    if (node is FieldFormalParameter) {
-      ConstructorDeclaration constructorDecl =
-          node.getAncestor((p) => p is ConstructorDeclaration);
-      if (constructorDecl != null) {
-        // Compute fields already referenced
-        List<String> referencedFields = new List<String>();
-        for (FormalParameter param in constructorDecl.parameters.parameters) {
-          if (param is FieldFormalParameter) {
-            SimpleIdentifier fieldId = param.identifier;
-            if (fieldId != null && fieldId != request.target.entity) {
-              String fieldName = fieldId.name;
-              if (fieldName != null && fieldName.length > 0) {
-                referencedFields.add(fieldName);
-              }
-            }
-          }
-        }
-
-        // Add suggestions for fields that are not already referenced
-        ClassDeclaration classDecl =
-            constructorDecl.getAncestor((p) => p is ClassDeclaration);
-        for (ClassMember member in classDecl.members) {
-          if (member is FieldDeclaration && !member.isStatic) {
-            for (VariableDeclaration varDecl in member.fields.variables) {
-              SimpleIdentifier fieldId = varDecl.name;
-              if (fieldId != null) {
-                String fieldName = fieldId.name;
-                if (fieldName != null && fieldName.length > 0) {
-                  if (!referencedFields.contains(fieldName)) {
-                    CompletionSuggestion suggestion =
-                        createFieldSuggestion(request.source, member, varDecl);
-                    if (suggestion != null) {
-                      request.addSuggestion(suggestion);
-                    }
-                  }
-                }
-              }
-            }
-          }
-        }
-      }
-    } else {
-      // This should never be called with a case not handled above.
-      assert(false);
-    }
-    return true;
-  }
-
-  @override
-  Future<bool> computeFull(AstNode node) {
-    // This should never be called; we should always be able to compute
-    // suggestions and return true in computeFast method.
-    assert(false);
-    return null;
-  }
-}
-
-/**
  * An [AstNode] vistor for determining which suggestion builder
  * should be used to build invocation/access suggestions.
  */
@@ -179,11 +112,6 @@ class _InvocationAstVisitor extends GeneralizingAstVisitor<SuggestionBuilder> {
   }
 
   @override
-  SuggestionBuilder visitFieldFormalParameter(FieldFormalParameter node) {
-    return new _FieldFormalSuggestionBuilder(request);
-  }
-
-  @override
   SuggestionBuilder visitMethodInvocation(MethodInvocation node) {
     return new _ExpressionSuggestionBuilder(request);
   }