Report EQUALITY_CANNOT_BE_EQUALITY_OPERAND

editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/parser/Parser.java

Index: editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/parser/Parser.java
diff --git a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/parser/Parser.java b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/parser/Parser.java
index a7e204d1e211385175f8d64b6d42eabdd0996036..ff3404313762b3bbf7618922402d03191da00fff 100644
--- a/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/parser/Parser.java
+++ b/editor/tools/plugins/com.google.dart.engine/src/com/google/dart/engine/parser/Parser.java
@@ -2483,9 +2483,14 @@ public class Parser {
     } else {
       expression = parseRelationalExpression();
     }
+    boolean leftEqualityExpression = false;
     while (currentToken.getType().isEqualityOperator()) {
       Token operator = getAndAdvance();
+      if (leftEqualityExpression) {
+        reportError(ParserErrorCode.EQUALITY_CANNOT_BE_EQUALITY_OPERAND, expression);
+      }
       expression = new BinaryExpression(expression, operator, parseRelationalExpression());
+      leftEqualityExpression = true;
     }
     return expression;
   }