Remove triple-shift from dart2js.

pkg/compiler/lib/src/compiler.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.
 
 library dart2js.compiler_base;
 
 import 'dart:async' show
     EventSink,
     Future;
 
@@ skipping 1779 matching lines @@
       // end that is null. Otherwise, we probably know the current
       // URI.
       throw 'Cannot find tokens to produce error message.';
     }
     if (uri == null && currentElement != null) {
       uri = currentElement.compilationUnit.script.resourceUri;
       assert(invariant(currentElement, () {
 
         bool sameToken(Token token, Token sought) {
           if (token == sought) return true;
-          if (token.stringValue == '>>' ||
-              token.stringValue == '>>>') {
-            // `>>` and `>>>` are converted to `>` in the parser when needed.
+          if (token.stringValue == '>>') {
+            // `>>` is converted to `>` in the parser when needed.
             return sought.stringValue == '>' &&
                 token.charOffset <= sought.charOffset &&
                 sought.charOffset < token.charEnd;
           }
           return false;
         }
 
         /// Check that [begin] and [end] can be found between [from] and [to].
         validateToken(Token from, Token to) {
           if (from == null || to == null) return true;
@@ skipping 389 matching lines @@
     if (_otherDependencies == null) {
       _otherDependencies = new Setlet<Element>();
     }
     _otherDependencies.add(element.implementation);
   }
 
   Iterable<Element> get otherDependencies {
     return _otherDependencies != null ? _otherDependencies : const <Element>[];
   }
 }