Make DOMWrapperWorld::current() callable from workers

Source/bindings/v8/V8Binding.cpp

Index: Source/bindings/v8/V8Binding.cpp
diff --git a/Source/bindings/v8/V8Binding.cpp b/Source/bindings/v8/V8Binding.cpp
index bb61f486a7bc623be6b55eb0d97e194e239f1344..dbb1a8ddb39ac100822cdad8a8be5b05e25781e1 100644
--- a/Source/bindings/v8/V8Binding.cpp
+++ b/Source/bindings/v8/V8Binding.cpp
@@ -554,11 +554,9 @@ v8::Local<v8::Context> toV8Context(ExecutionContext* context, DOMWrapperWorld* w
 {
     ASSERT(context);
     if (context->isDocument()) {
-        ASSERT(world);
         if (LocalFrame* frame = toDocument(context)->frame())
             return frame->script().windowShell(world)->context();
     } else if (context->isWorkerGlobalScope()) {
-        ASSERT(!world);
         if (WorkerScriptController* script = toWorkerGlobalScope(context)->script())
             return script->context();
     }