Kill worker process by way of a sync IPC message before it cleans up.

content/worker/worker_thread.cc

Index: content/worker/worker_thread.cc
diff --git a/content/worker/worker_thread.cc b/content/worker/worker_thread.cc
index 4cabcb4b34c9cee7e1556467b9dd6d56c666c2fb..fd9fce508feac3c4df71605a584b0d77ebbca419 100644
--- a/content/worker/worker_thread.cc
+++ b/content/worker/worker_thread.cc
@@ -56,6 +56,13 @@ WorkerThread::WorkerThread() {
   SetRuntimeFeaturesDefaultsAndUpdateFromArgs(command_line);
 }
 
+void WorkerThread::OnProcessFinalRelease() {
+  // The worker process is to be shut down gracefully. Ask the browser
+  // process to shut it down forcefully instead and wait on the message, so that
+  // there are no races between threads when the process is shutting down.
+  Send(new WorkerProcessHostMsg_ForceKillWorker());

[michaeln, 2013/09/16 22:00:41]

Does it not work to have this line as the first and only line of
WorkerThread::Shutdown?

In the 'final release' sequence, there's an opportunity for the browser process
to change its mind about shutting down the  child afterall. With current code,
when WorkerProcessHost::CanShutdown() returns false, the 'final release' doesn't
result in a shutdown. This CL changes that behavior and will kill the process
even if CanShutdown says 'false'. Not sure we want that behavior change.

[Mustafa Acer, 2013/09/16 22:08:44]

It doesn't work.
How about overriding ChildThread::OnShutdown then? That should be called after
the browser says that the process can be shut down.

+}
+
 WorkerThread::~WorkerThread() {
 }