Revert "Add DartEditBuilder.writeTopLevelElementReference()."

This reverts commit 23a1534432ae038b4d6eedc8f3a98b6a86bf1673.

Reason for revert: a different API is more suitable.

Original change's description:
> Add DartEditBuilder.writeTopLevelElementReference().
> 
> R=​brianwilkerson@google.com, paulberry@google.com
> 
> Change-Id: Ib1511a91a7f021002e4b2f109cebe82b2814985d
> Reviewed-on: https://dart-review.googlesource.com/53687
> Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
> Reviewed-by: Paul Berry <paulberry@google.com>

TBR=paulberry@google.com,scheglov@google.com,brianwilkerson@google.com

# Not skipping CQ checks because original CL landed > 1 day ago.

Change-Id: Ia5a8f1976d8ffc21de5672cce3dee73c3297cfcf
Reviewed-on: https://dart-review.googlesource.com/53881
Reviewed-by: Konstantin Shcheglov <scheglov@google.com>
Commit-Queue: Konstantin Shcheglov <scheglov@google.com>
diff --git a/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart b/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
index 636af2a..19623cc 100644
--- a/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
+++ b/pkg/analyzer_plugin/lib/src/utilities/change_builder/change_builder_dart.dart
@@ -580,34 +580,6 @@
   }
 
   @override
-  void writeTopLevelElementReference(Element element) {
-    if (element?.enclosingElement is! CompilationUnitElement) {
-      throw new ArgumentError('The element $element is not top-level.');
-    }
-    if (element is! FunctionElement && element is! PropertyAccessorElement) {
-      throw new ArgumentError(
-          'The element $element can only be a top-level function or accessor.');
-    }
-
-    LibraryElement definingLibrary = element.library;
-    LibraryElement importingLibrary = dartFileEditBuilder.unit.element.library;
-
-    // TODO(scheglov) Extract this code (it is already used twice).
-    // TODO(scheglov) Consider updating `show` combinator to show the element.
-    ImportElement existingImport = _getImportElement(element, importingLibrary);
-    if (existingImport != null) {
-      if (existingImport.prefix != null) {
-        write(existingImport.prefix.displayName);
-        write('.');
-      }
-    } else {
-      importLibrary(definingLibrary.source);
-    }
-
-    write(element.displayName);
-  }
-
-  @override
   bool writeType(DartType type,
       {bool addSupertypeProposals: false,
       String groupName,
diff --git a/pkg/analyzer_plugin/lib/utilities/change_builder/change_builder_dart.dart b/pkg/analyzer_plugin/lib/utilities/change_builder/change_builder_dart.dart
index 5df9c02..86545f0 100644
--- a/pkg/analyzer_plugin/lib/utilities/change_builder/change_builder_dart.dart
+++ b/pkg/analyzer_plugin/lib/utilities/change_builder/change_builder_dart.dart
@@ -223,13 +223,6 @@
   void writeParametersMatchingArguments(ArgumentList arguments);
 
   /**
-   * Write the code that references the given top-level [element] (a top-level
-   * function, or a property accessor). If the [element] is not a top-level
-   * element then [ArgumentError] is thrown.
-   */
-  void writeTopLevelElementReference(Element element);
-
-  /**
    * Write the code for a type annotation for the given [type]. If the [type] is
    * either `null` or represents the type 'dynamic', then the behavior depends
    * on whether a type is [required]. If [required] is `true`, then 'var' will
diff --git a/pkg/analyzer_plugin/test/src/utilities/change_builder/change_builder_dart_test.dart b/pkg/analyzer_plugin/test/src/utilities/change_builder/change_builder_dart_test.dart
index d5691de..fdb1008 100644
--- a/pkg/analyzer_plugin/test/src/utilities/change_builder/change_builder_dart_test.dart
+++ b/pkg/analyzer_plugin/test/src/utilities/change_builder/change_builder_dart_test.dart
@@ -1577,78 +1577,6 @@
     expect(edit.replacement, equalsIgnoringWhitespace('String s, int i'));
   }
 
-  test_writeTopLevelElementReference_hasImport_noPrefix() async {
-    String aPath = provider.convertPath('/a.dart');
-    addSource(aPath, 'const a = 42;');
-
-    String path = provider.convertPath('/test.dart');
-    String content = r'''
-import 'a.dart';
-''';
-    addSource(path, content);
-
-    var aElement = await _getTopLevelAccessorElement(aPath, 'a');
-
-    DartChangeBuilderImpl builder = new DartChangeBuilder(session);
-    await builder.addFileEdit(path, (DartFileEditBuilder builder) {
-      builder.addInsertion(content.length - 1, (DartEditBuilder builder) {
-        builder.write('const v = ');
-        builder.writeTopLevelElementReference(aElement);
-        builder.write(';');
-      });
-    });
-    SourceEdit edit = getEdit(builder);
-    expect(edit.replacement, equalsIgnoringWhitespace('const v = a;'));
-  }
-
-  test_writeTopLevelElementReference_hasImport_prefix() async {
-    String aPath = provider.convertPath('/a.dart');
-    addSource(aPath, 'const a = 42;');
-
-    String path = provider.convertPath('/test.dart');
-    String content = r'''
-import 'a.dart' as p;
-''';
-    addSource(path, content);
-
-    var aElement = await _getTopLevelAccessorElement(aPath, 'a');
-
-    DartChangeBuilderImpl builder = new DartChangeBuilder(session);
-    await builder.addFileEdit(path, (DartFileEditBuilder builder) {
-      builder.addInsertion(content.length - 1, (DartEditBuilder builder) {
-        builder.write('const v = ');
-        builder.writeTopLevelElementReference(aElement);
-        builder.write(';');
-      });
-    });
-    SourceEdit edit = getEdit(builder);
-    expect(edit.replacement, equalsIgnoringWhitespace('const v = p.a;'));
-  }
-
-  test_writeTopLevelElementReference_noImport() async {
-    String aPath = provider.convertPath('/a.dart');
-    addSource(aPath, 'const a = 42;');
-
-    String path = provider.convertPath('/test.dart');
-    String content = '';
-    addSource(path, content);
-
-    var aElement = await _getTopLevelAccessorElement(aPath, 'a');
-
-    DartChangeBuilderImpl builder = new DartChangeBuilder(session);
-    await builder.addFileEdit(path, (DartFileEditBuilder builder) {
-      builder.addInsertion(content.length - 1, (DartEditBuilder builder) {
-        builder.write('const v = ');
-        builder.writeTopLevelElementReference(aElement);
-        builder.write(';');
-      });
-    });
-    List<SourceEdit> edits = getEdits(builder);
-    expect(edits, hasLength(2));
-    expect(edits[0].replacement, equalsIgnoringWhitespace("import 'a.dart';"));
-    expect(edits[1].replacement, equalsIgnoringWhitespace('const v = a;'));
-  }
-
   test_writeType_dynamic() async {
     String path = provider.convertPath('/test.dart');
     String content = 'class A {}';
@@ -1984,12 +1912,6 @@
     return result.element.getType(name);
   }
 
-  Future<PropertyAccessorElement> _getTopLevelAccessorElement(
-      String path, String name) async {
-    UnitElementResult result = await driver.getUnitElement(path);
-    return result.element.accessors.firstWhere((v) => v.name == name);
-  }
-
   Future<DartType> _getType(String path, String name) async {
     ClassElement classElement = await _getClassElement(path, name);
     return classElement.type;