- Trial balloon for removal of argument definition test.

runtime/vm/parser.cc

Index: runtime/vm/parser.cc
===================================================================
--- runtime/vm/parser.cc	(revision 24437)
+++ runtime/vm/parser.cc	(working copy)
@@ -9830,8 +9830,6 @@
     } else {
       primary = new PrimaryNode(TokenPos(), Symbols::Super());
     }
-  } else if (CurrentToken() == Token::kCONDITIONAL) {
-    primary = ParseArgumentDefinitionTest();
   } else {
     UnexpectedToken();
   }
@@ -10031,12 +10029,6 @@
     case Token::kINDEX:
       SkipCompoundLiteral();
       break;
-    case Token::kCONDITIONAL:
-      ConsumeToken();
-      if (IsIdentifier()) {
-        ConsumeToken();
-      }
-      break;
     default:
       if (IsIdentifier()) {
         ConsumeToken();  // Handle pseudo-keyword identifiers.