Use make_scoped_refptr() instead of manual AddRef()/Release() in ipc.

ipc/ipc_channel_proxy.cc

Index: ipc/ipc_channel_proxy.cc
diff --git a/ipc/ipc_channel_proxy.cc b/ipc/ipc_channel_proxy.cc
index 97852163076649f01c5a1fdefe6f4b8624841919..feca4eb956211f7e6b0242dc52e6b721e17cda25 100644
--- a/ipc/ipc_channel_proxy.cc
+++ b/ipc/ipc_channel_proxy.cc
@@ -196,9 +196,6 @@ void ChannelProxy::Context::OnAddFilter(MessageFilter* filter) {
   // so that the filter gets access to the Channel.
   if (channel_)
     filter->OnFilterAdded(channel_);
-
-  // Balances the AddRef in ChannelProxy::AddFilter.
-  filter->Release();
 }
 
 // Called on the IPC::Channel thread
@@ -317,16 +314,20 @@ bool ChannelProxy::Send(Message* message) {
 }
 
 void ChannelProxy::AddFilter(MessageFilter* filter) {
-  // We want to addref the filter to prevent it from
-  // being destroyed before the OnAddFilter call is invoked.
-  filter->AddRef();
-  context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
-      context_.get(), &Context::OnAddFilter, filter));
+  context_->ipc_message_loop()->PostTask(
+      FROM_HERE,
+      NewRunnableMethod(
+          context_.get(),
+          &Context::OnAddFilter,
+          make_scoped_refptr(filter)));
 }
 
 void ChannelProxy::RemoveFilter(MessageFilter* filter) {
-  context_->ipc_message_loop()->PostTask(FROM_HERE, NewRunnableMethod(
-      context_.get(), &Context::OnRemoveFilter, filter));
+  context_->ipc_message_loop()->PostTask(
+      FROM_HERE, NewRunnableMethod(
+          context_.get(),
+          &Context::OnRemoveFilter,
+          make_scoped_refptr(filter)));
 }
 
 void ChannelProxy::ClearIPCMessageLoop() {