Revert "Revert "Support multiple DOM isolates and tweak devtools frontend to better handle large #s…

Source/bindings/core/dart/DartJsInterop.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 254 matching lines @@
         return handle;
 
     // Unwrap objects passed from Dart to JS that are being passed back to
     // Dart. FIXME: we do not yet handle unwrapping JS functions passed
     // from Dart to JS as we have to wrap them with true JS Function objects.
     // If this use case is important we can support it at the cost of hanging
     // an extra expando off the JS function wrapping the Dart function.
     if (DartHandleProxy::isDartProxy(v8Handle)) {
         DartPersistentValue* scriptValue = DartHandleProxy::readPointerFromProxy(v8Handle);
         ASSERT(scriptValue->isIsolateAlive());
-        return scriptValue->value();
+        // If the isolate does not match we fall back to using the existing JS
+        // wrapper for the Dart object so that simple cases that would work in
+        // Dart2Js work. We could alternately throw an exception here.
+        if (scriptValue->isolate() == Dart_CurrentIsolate()) {
+            return scriptValue->value();
+        }
     }
 
     return JsObject::toDart(object);
 }
 
 Dart_Handle JsObject::toDart(v8::Local<v8::Object> object)
 {
     // FIXME: perform caching so that === can be used.
     if (object->IsFunction()) {
         RefPtr<JsFunction> jsFunction = JsFunction::create(object.As<v8::Function>());
@@ skipping 758 matching lines @@
 {
     for (intptr_t i = 0; nativeEntries[i].nativeFunction != 0; i++) {
         if (nf == nativeEntries[i].nativeFunction) {
             return reinterpret_cast<const uint8_t*>(nativeEntries[i].name);
         }
     }
     return 0;
 }
 
 }