Pepper proxy: make the browser sender handle the proxy lock properly.

ppapi/proxy/plugin_dispatcher.cc

Index: ppapi/proxy/plugin_dispatcher.cc
diff --git a/ppapi/proxy/plugin_dispatcher.cc b/ppapi/proxy/plugin_dispatcher.cc
index 29bcb4ab00c215f754f592ab3bd48684f938628a..137031d9cb251c1d55d3902e06200695da3030a6 100644
--- a/ppapi/proxy/plugin_dispatcher.cc
+++ b/ppapi/proxy/plugin_dispatcher.cc
@@ -192,6 +192,10 @@ bool PluginDispatcher::Send(IPC::Message* msg) {
   if (msg->is_sync()) {
     // Synchronous messages might be re-entrant, so we need to drop the lock.
     ProxyAutoUnlock unlock;
+
+    // TODO(yzshen): Make sending message thread-safe. It may be accessed from
+    // non-main threads. Moreover, since the proxy lock has been released, it
+    // may be accessed by multiple threads at the same time.

[brettw, 2012/11/27 00:49:15]

Is there a bug on this?

[yzshen1, 2012/11/30 04:29:13]

Yes. Although I haven't seen any bug reports, the Send() implementation doesn't
look safe. I will take a closer look and fix it.

     return Dispatcher::Send(msg);
   }
   return Dispatcher::Send(msg);