Remove most superfluous getter arguments from dart2js.

dart/lib/compiler/implementation/tree/dartstring.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.
 
 /**
  * The [DartString] type represents a Dart string value as a sequence of Unicode
  * Scalar Values.
  * After parsing, any valid [LiteralString] will contain a [DartString]
  * representing its content after removing quotes and resolving escapes in
  * its source.
@@ skipping 33 matching lines @@
   abstract SourceString get source();
 }
 
 
 /**
  * A [DartString] where the content is represented by an actual [String].
  */
 class LiteralDartString extends DartString {
   final String string;
   const LiteralDartString(this.string);
-  int get length() => string.length;
+  int get length => string.length;
   Iterator<int> iterator() => new StringCodeIterator(string);
   String slowToString() => string;
-  SourceString get source() => new StringWrapper(string);
+  SourceString get source => new StringWrapper(string);
 }
 
 /**
  * A [DartString] where the content comes from a slice of the program source.
  */
 class SourceBasedDartString extends DartString {
   String toStringCache = null;
   final SourceString source;
   final int length;
   SourceBasedDartString(this.source, this.length);
@@ skipping 49 matching lines @@
         this.right = right,
         length = left.length + right.length;
 
   Iterator<int> iterator() => new ConsDartStringIterator(this);
 
   String slowToString() {
     if (toStringCache !== null) return toStringCache;
     toStringCache = left.slowToString().concat(right.slowToString());
     return toStringCache;
   }
-  SourceString get source() => new StringWrapper(slowToString());
+  SourceString get source => new StringWrapper(slowToString());
 }
 
 class ConsDartStringIterator implements Iterator<int> {
   Iterator<int> current;
   DartString right;
   bool hasNextLookAhead;
   ConsDartStringIterator(ConsDartString cons)
       : current = cons.left.iterator(),
         right = cons.right {
     hasNextLookAhead = current.hasNext();
@@ skipping 62 matching lines @@
       for (int i = 0; i < 3; i++) {
         code = source.next();
         value = value * 16 + hexDigitValue(code);
       }
       return value;
     }
     return code;
   }
 }