Get IPC working for Indexed DB in shared workers.

content/renderer/indexed_db/indexed_db_dispatcher.cc

Index: content/renderer/indexed_db/indexed_db_dispatcher.cc
diff --git a/content/renderer/indexed_db/indexed_db_dispatcher.cc b/content/renderer/indexed_db/indexed_db_dispatcher.cc
index 2770fbbeb81254065242e8f67961014a22623b47..00153d59c07050d445a27363eefa969082b3d034 100644
--- a/content/renderer/indexed_db/indexed_db_dispatcher.cc
+++ b/content/renderer/indexed_db/indexed_db_dispatcher.cc
@@ -181,9 +181,6 @@ void IndexedDBDispatcher::RequestIDBFactoryOpen(
 
   if (!web_frame)
     return; // We must be shutting down.
-  RenderViewImpl* render_view = RenderViewImpl::FromWebView(web_frame->view());

[dgrogan, 2012/02/09 22:46:06]

This always fails in the shared worker.  I would have thought that there would
no webFrame in the shared worker either but apparently there is.

I don't know how useful this check was in the renderer, anyway.

[jsbell, 2012/02/09 23:23:56]

Being paranoid, I see this pattern used in a few other places for similar early
exit.... jam@ ?

[michaeln, 2012/02/09 23:59:40]

These render_view checks are probably here for good reason (script running in a
detached iframe?) and probably shouldn't be removed without understanding that
reason. You can distinguish between the 'worker' vs 'document' case by looking
at the value of CurrentWorkerId(). We should be able to conditionally skip the
sanity-tests for web_frame/render_view in the worker case.

The non-null value of 'web_frame' in the worker case comes from
IDBFactoryBackendProxy.

void IDBFactoryBackendProxy::openFromWorker(const String& name, IDBCallbacks*
callbacks, PassRefPtr<SecurityOrigin> prpOrigin, WorkerContext* context, const
String& dataDir)
{
#if ENABLE(WORKERS)
    WebSecurityOrigin origin(prpOrigin);
    if (!allowIDBFromWorkerThread(context, name, origin)) {
        callbacks->onError(WebIDBDatabaseError(0, "The user denied permission to
access the database."));
        return;
    }
    WorkerLoaderProxy* workerLoaderProxy =
&context->thread()->workerLoaderProxy();
    WebWorkerBase* webWorker = static_cast<WebWorkerBase*>(workerLoaderProxy);
    WebFrame* webFrame = webWorker->view()->mainFrame();
    m_webIDBFactory->open(name, new WebIDBCallbacksImpl(callbacks), origin,
webFrame, dataDir);
#endif
}

Since we're on the worker context thread, it'd probably be safer to pass NULL
for webFrame at this callsite since WebFrame is not thread-safe.

-  if (!render_view)
-    return; // We must be shutting down.
 
   IndexedDBHostMsg_FactoryOpen_Params params;
   params.thread_id = CurrentWorkerId();