An exprimental fix for Bug 65940....

chrome/common/child_thread.cc

Index: chrome/common/child_thread.cc
===================================================================
--- chrome/common/child_thread.cc	(revision 68724)
+++ chrome/common/child_thread.cc	(working copy)
@@ -71,6 +71,11 @@
 
   channel_->RemoveFilter(sync_message_filter_.get());
 
+  // Close this channel before resetting the message loop attached to it so
+  // the message loop can call ChannelProxy::Context::OnChannelClosed(), which
+  // releases the reference count to this channel.
+  channel_->Close();
+
   // The ChannelProxy object caches a pointer to the IPC thread, so need to
   // reset it as it's not guaranteed to outlive this object.
   // NOTE: this also has the side-effect of not closing the main IPC channel to