Revert 167276 "Remove isolatedWorldForEnteredContext() and isola..."

trunk/Source/bindings/v8/DOMWrapperWorld.cpp

Index: trunk/Source/bindings/v8/DOMWrapperWorld.cpp
===================================================================
--- trunk/Source/bindings/v8/DOMWrapperWorld.cpp	(revision 167359)
+++ trunk/Source/bindings/v8/DOMWrapperWorld.cpp	(working copy)
@@ -62,10 +62,14 @@
 
 DOMWrapperWorld* DOMWrapperWorld::current(v8::Isolate* isolate)
 {
+    ASSERT(isolate->InContext());
     v8::Handle<v8::Context> context = isolate->GetCurrentContext();
-    if (context.IsEmpty() || !toDOMWindow(context))
+    if (!toDOMWindow(context))
         return 0;
-    return world(context);
+    ASSERT(isMainThread());
+    if (DOMWrapperWorld* world = isolatedWorld(context))
+        return world;
+    return mainWorld();
 }
 
 DOMWrapperWorld* DOMWrapperWorld::mainWorld()