Push add*Edit helpers into SourceChange.

pkg/analysis_server/tool/spec/codegen_dart_protocol.dart

Index: pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
diff --git a/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart b/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
index b473b2534e14550c46d68f4d3ae1531413ee390a..2cf47325f39bc0b33a773bf3e0a70a5779f785ae 100644
--- a/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
+++ b/pkg/analysis_server/tool/spec/codegen_dart_protocol.dart
@@ -563,6 +563,17 @@ class CodegenProtocolVisitor extends HierarchicalApiVisitor with CodeGenerator {
         writeln('void addEdit(String file, int fileStamp, SourceEdit edit) =>');
         writeln('    _addEditToSourceChange(this, file, fileStamp, edit);');
         writeln();
+        docComment(
+            [new dom.Text('Adds [edit] to the [FileEdit] for the given [source].')]);
+        writeln('void addSourceEdit(engine.AnalysisContext context,');
+        writeln(    'engine.Source source, SourceEdit edit) =>');
+        writeln('    _addSourceEditToSourceChange(this, context, source, edit);');
+        writeln();
+        docComment(
+            [new dom.Text('Adds [edit] to the [FileEdit] for the given [element].')]);
+        writeln('void addElementEdit(engine.Element element, SourceEdit edit) =>');
+        writeln('    _addElementEditToSourceChange(this, element, edit);');
+        writeln();
         docComment([new dom.Text('Adds the given [FileEdit].')]);
         writeln('void addFileEdit(SourceFileEdit edit) {');
         indent(() {