Assume a method can be torn off, if it's accessible through reflection.

sdk/lib/_internal/compiler/implementation/js_emitter/container_builder.dart

 // Copyright (c) 2013, 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.
 
 part of dart2js.js_emitter;
 
 /// This class should morph into something that makes it easy to build
 /// JavaScript representations of libraries, class-sides, and instance-sides.
 /// Initially, it is just a placeholder for code that is moved from
 /// [CodeEmitterTask].
@@ skipping 327 matching lines @@
                member.isGenerativeConstructor ||
                member.isAccessor) {
       addMemberMethod(member, builder);
     } else {
       compiler.internalError(member,
           'Unexpected kind: "${member.kind}".');
     }
     if (member.isInstanceMember) emitExtraAccessors(member, builder);
   }
 
+  bool _isOperator(FunctionElement member) {
+    // TODO(18740): there must be a better way to know if an element is an
+    // operator.
+    return Elements.operatorNameToIdentifier(member.name) != member.name;

[herhut, 2014/05/09 07:23:18]

Why do we use two different ways to determine whether it is an operator?

[floitsch, 2014/05/09 07:53:19]

I didn't want to change unrelated code.

+  }
+
   void addMemberMethod(FunctionElement member, ClassBuilder builder) {
     if (member.isAbstract) return;
     jsAst.Expression code = backend.generatedCode[member];
     if (code == null) return;
     String name = namer.getNameOfMember(member);
     task.interceptorEmitter.recordMangledNameOfMemberMethod(member, name);
     FunctionSignature parameters = member.functionSignature;
     bool needsStubs = !parameters.optionalParameters.isEmpty;
     bool canTearOff = false;
     bool isClosure = false;
     bool isNotApplyTarget = !member.isFunction ||
                             member.isConstructor ||
                             member.isAccessor;
     String tearOffName;
+
+    final bool canBeReflected = backend.isAccessibleByReflection(member);
+
     if (isNotApplyTarget) {
       canTearOff = false;
     } else if (member.isInstanceMember) {
       if (member.enclosingClass.isClosure) {
         canTearOff = false;
         isClosure = true;
       } else {
         // Careful with operators.
-        canTearOff = compiler.codegenWorld.hasInvokedGetter(member, compiler);
+        canTearOff =
+            compiler.codegenWorld.hasInvokedGetter(member, compiler) ||
+            (canBeReflected && !_isOperator(member));
         assert(!needsSuperGetter(member) || canTearOff);
         tearOffName = namer.getterName(member);
       }
     } else {
       canTearOff =
-          compiler.codegenWorld.staticFunctionsNeedingGetter.contains(member);
+          compiler.codegenWorld.staticFunctionsNeedingGetter.contains(member) ||
+          canBeReflected;
       tearOffName = namer.getStaticClosureName(member);
     }
     final bool canBeApplied = compiler.enabledFunctionApply &&
                               compiler.world.getMightBePassedToApply(member);
 
-    final bool canBeReflected = backend.isAccessibleByReflection(member);
     final bool needStructuredInfo =
         canTearOff || canBeReflected || canBeApplied;
     if (!needStructuredInfo) {
       builder.addProperty(name, code);
       if (needsStubs) {
         addParameterStubs(
             member,
             (Selector selector, jsAst.Fun function) {
               builder.addProperty(namer.invocationName(selector), function);
             });
@@ skipping 145 matching lines @@
     } else if (isClosure && canBeApplied) {
       expressions.add(js.string(member.name));
     }
     builder.addProperty(name, new jsAst.ArrayInitializer.from(expressions));
   }
 
   void addMemberField(VariableElement member, ClassBuilder builder) {
     // For now, do nothing.
   }
 }