Never lock the Pepper proxy lock on the IO thread

ppapi/proxy/plugin_message_filter.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ppapi/proxy/plugin_message_filter.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "ipc/ipc_channel.h"
 #include "ppapi/proxy/ppapi_messages.h"
@@ skipping 36 matching lines @@
   return handled;
 }
 
 bool PluginMessageFilter::Send(IPC::Message* msg) {
   if (sender_)
     return sender_->Send(msg);
   delete msg;
   return false;
 }
 
+void PluginMessageFilter::AddResourceMessageFilter(
+    const scoped_refptr<ResourceMessageFilter>& filter) {
+  resource_filters_.push_back(filter);
+}
+
 // static
 void PluginMessageFilter::DispatchResourceReplyForTest(
     const ResourceMessageReplyParams& reply_params,
     const IPC::Message& nested_msg) {
   DispatchResourceReply(reply_params, nested_msg);
 }
 
 void PluginMessageFilter::OnMsgReserveInstanceId(PP_Instance instance,
                                                  bool* usable) {
   // If |seen_instance_ids_| is set to NULL, we are not supposed to see this
   // message.
   CHECK(seen_instance_ids_);
   // See the message definition for how this works.
   if (seen_instance_ids_->find(instance) != seen_instance_ids_->end()) {
     // Instance ID already seen, reject it.
     *usable = false;
     return;
   }
 
   // This instance ID is new so we can return that it's usable and mark it as
   // used for future reference.
   seen_instance_ids_->insert(instance);
   *usable = true;
 }
 
 void PluginMessageFilter::OnMsgResourceReply(
     const ResourceMessageReplyParams& reply_params,
     const IPC::Message& nested_msg) {
+  for (const auto& filter_ptr : resource_filters_) {
+    if (filter_ptr->OnResourceReplyReceived(reply_params, nested_msg))
+      return;
+  }
   scoped_refptr<base::MessageLoopProxy> target =
       resource_reply_thread_registrar_->GetTargetThread(reply_params,
                                                         nested_msg);
-
-  if (!target.get()) {
-    DispatchResourceReply(reply_params, nested_msg);
-  } else {
-    target->PostTask(
-        FROM_HERE,
-        base::Bind(&DispatchResourceReply, reply_params, nested_msg));
-  }
+  target->PostTask(
+      FROM_HERE, base::Bind(&DispatchResourceReply, reply_params, nested_msg));
 }
 
 // static
 void PluginMessageFilter::DispatchResourceReply(
     const ResourceMessageReplyParams& reply_params,
     const IPC::Message& nested_msg) {
   ProxyAutoLock lock;
   Resource* resource = PpapiGlobals::Get()->GetResourceTracker()->GetResource(
       reply_params.pp_resource());
   if (!resource) {
     DVLOG_IF(1, reply_params.sequence() != 0)
         << "Pepper resource reply message received but the resource doesn't "
            "exist (probably has been destroyed).";
     return;
   }
   resource->OnReplyReceived(reply_params, nested_msg);
 }
 
 }  // namespace proxy
 }  // namespace ppapi