dart2dart: Test cases for better code coverage in dart_tree rewritings.

sdk/lib/_internal/compiler/implementation/dart_backend/dart_tree.dart

 // Copyright (c) 2014, 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 dart_tree;
 
 import '../dart2jslib.dart' as dart2js;
 import '../elements/elements.dart'
     show Element, FunctionElement, FunctionSignature, ParameterElement,
          ClassElement;
@@ skipping 1384 matching lines @@
           makeCondition(node.condition, false, liftNots: false),
           putInBooleanContext(node.thenExpression));
     }
     // x ? true : y ==> x || y  (if y if known to be boolean)
     if (isBooleanValued(node.elseExpression) && isTrue(node.thenExpression)) {
       return new LogicalOperator.or(
           makeCondition(node.condition, true, liftNots: false),
           putInBooleanContext(node.elseExpression));
     }
     // x ? false : y ==> !x && y  (if y is known to be a boolean)
-    if (isBooleanValued(node.elseExpression) && isTrue(node.thenExpression)) {
+    if (isBooleanValued(node.elseExpression) && isFalse(node.thenExpression)) {
       return new LogicalOperator.and(
           makeCondition(node.condition, false, liftNots: false),
           putInBooleanContext(node.elseExpression));
     }
 
     node.condition = makeCondition(node.condition, true);
 
     // !x ? y : z ==> x ? z : y
     if (node.condition is Not) {
       node.condition = (node.condition as Not).operand;
@@ skipping 155 matching lines @@
     }
   }
 
   /// Destructively updates each entry of [l] with the result of visiting it.
   void _rewriteList(List<Expression> l) {
     for (int i = 0; i < l.length; i++) {
       l[i] = visitExpression(l[i]);
     }
   }
 }