Support for typedef in checked mode.

sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart

Index: sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart
===================================================================
--- sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart	(revision 16128)
+++ sdk/lib/_internal/compiler/implementation/js_backend/emitter.dart	(working copy)
@@ -1112,6 +1112,16 @@
     }
   }
 
+  void emitTypedefChecksOn(DartType type, void emitTest(Element element)) {
+    for (TypedefElement typedef in checkedTypedefs) {
+      FunctionType typedefType =
+          typedef.computeType(compiler).unalias(compiler);
+      if (compiler.types.isSubtype(type, typedefType)) {
+        emitTest(typedef);
+      }
+    }
+  }
+
   /**
    * Generate "is tests" for [cls]: itself, and the "is tests" for the
    * classes it implements. We don't need to add the "is tests" of the
@@ -1137,14 +1147,7 @@
         generateInterfacesIsTests(compiler.functionClass,
                                   emitIsTest,
                                   generated);
-        FunctionType callType = call.computeType(compiler);
-        for (TypedefElement typedef in checkedTypedefs) {
-          FunctionType typedefType =
-              typedef.computeType(compiler).unalias(compiler);
-          if (compiler.types.isSubtype(callType, typedefType)) {
-            emitIsTest(typedef);
-          }
-        }
+        emitTypedefChecksOn(call.computeType(compiler), emitIsTest);
       }
     }
     for (DartType interfaceType in cls.interfaces) {
@@ -1282,6 +1285,7 @@
     buffer.add(functionBuffer);
     buffer.add('$N$n');
   }
+
   void emitStaticFunctionsWithNamer(CodeBuffer buffer,
                                     Map<Element, CodeBuffer> generatedCode,
                                     String functionNamer(Element element)) {
@@ -1324,6 +1328,10 @@
       // in case it is used in spawnFunction.
       String fieldName = namer.STATIC_CLOSURE_NAME_NAME;
       buffer.add('$fieldAccess.$fieldName$_=$_"$staticName"$N');
+      emitTypedefChecksOn(element.computeType(compiler), (Element typedef) {
+        String operator = namer.operatorIs(typedef);
+        buffer.add('$fieldAccess.$operator$_=${_}true$N');
+      });
     }
   }
 
@@ -1437,6 +1445,12 @@
       addParameterStubs(callElement, (String stubName, CodeBuffer memberValue) {
         boundClosureBuffer.add(',\n$_$stubName:$_$memberValue');
       });
+
+      emitTypedefChecksOn(member.computeType(compiler), (Element typedef) {
+        String operator = namer.operatorIs(typedef);
+        boundClosureBuffer.add(',\n$_$operator$_:${_}true');
+      });
+
       boundClosureBuffer.add("$n}$N");
 
       closureClass = namer.isolateAccess(closureClassElement);