Implementation of shared worker code path for WebView file system permission.

content/public/browser/content_browser_client.h

Index: content/public/browser/content_browser_client.h
diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
index 95a92fe262170676a1a7f2517af7c8715d633de0..46aba3e44e0b7481a96350df370a13be672c5687 100644
--- a/content/public/browser/content_browser_client.h
+++ b/content/public/browser/content_browser_client.h
@@ -345,10 +345,11 @@ class CONTENT_EXPORT ContentBrowserClient {
   // Allow the embedder to control if access to file system by a shared worker
   // is allowed.
   // This is called on the IO thread.
-  virtual bool AllowWorkerFileSystem(
+  virtual void RequestWorkerFileSystemAccessSync(

[Andrew T Wilson (Slow), 2014/06/20 22:04:27]

Why is this called ...AccessSync() - I'm assuming since you have a callback,
this is an Async call?

[Xi Han, 2014/06/23 02:51:13]

Sorry for the confusion. But this is a sync call, with delay reply. Initially we
implemented it in the way that we did for the Worker: just carry this IPC
reply_msg to the end, and write the result to it and send it. However, the
difficulty that we meet is that we have no way to send a IPC msg in both
aw_content_browser_client.cc and content_browser_client.cc, which need to give
default reply to the IPC msg (true or false). So we adopt the way to pass in a
callback, rather than IPC::Message* reply_msg. So aw_content_browser_client.cc
and content_browser_client.cc only need to give their own default replies, and
the worker_process_host.cc who passes the message will be responsible to send
the reply msg. 

Hope my explanation will help here. If you think the name is still confusing, we
can remove the Sync sufix and just use "RequestWorkerFileSystem". What do you
think?

[jam, 2014/06/23 07:02:00]

What does this line mean? If there's a delay reply, you mean the callback is
called back after this method returns right? if so it's async. that's how
chrome's implementation is done right now.

[Xi Han, 2014/06/23 20:43:34]

I see. Thank you for the explanation. All of the "sync" suffix are removed.

       const GURL& url,
       ResourceContext* context,
-      const std::vector<std::pair<int, int> >& render_frames);
+      const std::vector<std::pair<int, int> >& render_frames,
+      base::Callback<void(bool)> callback);
 
   // Allow the embedder to control if access to IndexedDB by a shared worker
   // is allowed.