Ensure clean up functions of MessageFilter are paired with their initialization functions

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 79b0299657764270fa7accd0c447f6dfbdc72fe8..a1571a43c2db7bbcb57a67a4b29f872f8151ef1c 100644
--- a/ipc/ipc_channel_proxy.cc
+++ b/ipc/ipc_channel_proxy.cc
@@ -212,6 +212,11 @@ void ChannelProxy::Context::OnChannelClosed() {
     return;
 
   for (auto& filter : pending_filters_) {
+    // OnFilterAdded and OnChannelConnected have not been called on
+    // MessageFilters in |pending_filters_|. Call them here to match
+    // OnChannelClosing and OnFilterRemoved.
+    filter->OnFilterAdded(nullptr);
+    filter->OnChannelConnected(peer_pid_);
     filter->OnChannelClosing();
     filter->OnFilterRemoved();
   }