Add StringSink and update StringBuffer.

sdk/lib/_internal/compiler/implementation/code_buffer.dart

 // Copyright (c) 2012, 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.
 
 part of dart2js;
 
 class CodeBuffer implements StringBuffer {
   StringBuffer buffer;
   List<CodeBufferMarker> markers;
   int lastBufferOffset = 0;
   int mappedRangeCounter = 0;
 
   CodeBuffer()
       : buffer = new StringBuffer(),
         markers = new List<CodeBufferMarker>();
 
   int get length => buffer.length;
 
   bool get isEmpty {
     return buffer.isEmpty;
   }
 
+  CodeBuffer add(var object) {
+    write(object);
+    return this;
+  }
   /**
    * Converts [object] to a string and adds it to the buffer. If [object] is a
    * [CodeBuffer], adds its markers to [markers].
    */
-  CodeBuffer add(var object) {
+  CodeBuffer write(var object) {
     if (object is CodeBuffer) {
       return addBuffer(object);
     }
     if (mappedRangeCounter == 0) setSourceLocation(null);
     buffer.add(object.toString());
     return this;
   }
 
+  CodeBuffer writeln(var object) {
+    return write(object).write("\n");
+  }
+
   CodeBuffer addBuffer(CodeBuffer other) {
     if (other.markers.length > 0) {
       CodeBufferMarker firstMarker = other.markers[0];
       int offsetDelta =
           buffer.length + firstMarker.offsetDelta - lastBufferOffset;
       markers.add(new CodeBufferMarker(offsetDelta,
                                        firstMarker.sourcePosition));
       for (int i = 1; i < other.markers.length; ++i) {
         markers.add(other.markers[i]);
       }
       lastBufferOffset = buffer.length + other.lastBufferOffset;
     }
     buffer.add(other.getText());
+    return this;
   }
 
   CodeBuffer addAll(Iterable<Object> iterable) {
     for (Object obj in iterable) {
-      add(obj);
+      write(obj);
     }
     return this;
   }
 
-  CodeBuffer addCharCode(int charCode) {
-    return add(new String.fromCharCodes([charCode]));
+  CodeBuffer addCharCode(int charCode) => writeCharCode(charCode);
+
+  CodeBuffer writeCharCode(int charCode) {
+    return write(new String.fromCharCodes([charCode]));
   }
 
   CodeBuffer clear() {
     buffer.clear();
     markers.clear();
     lastBufferOffset = 0;
     return this;
   }
 
   String toString() {
@@ skipping 27 matching lines @@
     });
   }
 }
 
 class CodeBufferMarker {
   final int offsetDelta;
   final sourcePosition;
 
   CodeBufferMarker(this.offsetDelta, this.sourcePosition);
 }