Ensure formatted CUs end with a newline (dartbug.com/13188).

pkg/analyzer_experimental/lib/src/services/writer.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library source_writer;
 
 
 class Line {
 
   final int lineLength;
@@ skipping 23 matching lines @@
   }
 
   bool isWhitespace() => tokens.every((tok) => tok is SpaceToken);
 
   void _indent(int n) {
     tokens.add(useTabs ? new TabToken(n) : new SpaceToken(n * spacesPerIndent));
   }
 
   String toString() {
     var buffer = new StringBuffer();
-    for (var tok in tokens) {
-      buffer.write(tok.toString());
-    }
+    tokens.forEach((tok) => buffer.write(tok.toString()));
     return buffer.toString();
   }
 
 }
 
 
 class LineToken {
 
   final String value;
 
@@ skipping 20 matching lines @@
 
 
 
 class SourceWriter {
 
   final StringBuffer buffer = new StringBuffer();
   Line currentLine;
 
   final String lineSeparator;
   int indentCount = 0;
-
+  
+  LineToken _lastToken;
+  
   SourceWriter({this.indentCount: 0, this.lineSeparator: NEW_LINE}) {
     currentLine = new Line(indent: indentCount);
   }
 
+  LineToken get lastToken => _lastToken;
+  
+  _addToken(LineToken token) {
+    _lastToken = token;
+    currentLine.addToken(token);
+  }
+  
   void indent() {
     ++indentCount;
   }
 
-  void unindent() {
-    --indentCount;
-  }
-
-  void print(x) {
-    currentLine.addToken(new LineToken(x));
-  }
-
   void newline() {
     if (currentLine.isWhitespace()) {
       currentLine.tokens.clear();
     }
-    currentLine.addToken(new NewlineToken(this.lineSeparator));
+    _addToken(new NewlineToken(this.lineSeparator));
     buffer.write(currentLine.toString());
     currentLine = new Line(indent: indentCount);
   }
 
   void newlines(int num) {
     while (num-- > 0) {
       newline();
     }
   }
 
+  void print(x) {
+    _addToken(new LineToken(x));
+  }
+  
+  void println(String s) {
+    print(s);
+    newline();
+  }
+  
   void space() {
     spaces(1);
   }
 
   void spaces(n) {
     currentLine.addSpaces(n);
   }
-
-  void println(String s) {
-    print(s);
-    newline();
+  
+  void unindent() {
+    --indentCount;
   }
-
+  
   String toString() {
     var source = new StringBuffer(buffer.toString());
     if (!currentLine.isWhitespace()) {
       source.write(currentLine);
     }
     return source.toString();
   }
 
 }
 
@@ skipping 44 matching lines @@
 
 String getTabs(int n) => n < TABS.length ? TABS[n] : repeat('\t', n);
 
 String repeat(String ch, int times) {
   var sb = new StringBuffer();
   for (var i = 0; i < times; ++i) {
     sb.write(ch);
   }
   return sb.toString();
 }