Implement ChildThread::shutdown and clear members that have refs into…

… blink

This enables classes deriving frmo ChildThread to cleanly shut down
WebKit

BUG=263034
R=jam@chromium.org

Review URL: https://chromiumcodereview.appspot.com/19641008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@213239 0039d316-1c4b-4281-b951-d872f2087c98

content/child/child_thread.cc

@@ -195,6 +195,12 @@ ChildThread::~ChildThread() {
   g_lazy_tls.Pointer()->Set(NULL);
 }
 
+void ChildThread::Shutdown() {
+  // Delete objects that hold references to blink so derived classes can
+  // safely shutdown blink in their Shutdown implementation.
+  file_system_dispatcher_.reset();
+}
+
 void ChildThread::OnChannelConnected(int32 peer_pid) {
   channel_connected_factory_.InvalidateWeakPtrs();
 }

content/child/child_thread.h

@@ -50,7 +50,7 @@ class CONTENT_EXPORT ChildThread : public IPC::Listener, public IPC::Sender {
   // has a thread that post tasks to ChildProcess::main_thread(), that thread
   // should be joined in Shutdown().
   virtual ~ChildThread();
-  virtual void Shutdown() = 0;
+  virtual void Shutdown();
 
   // IPC::Sender implementation:
   virtual bool Send(IPC::Message* msg) OVERRIDE;

content/gpu/gpu_child_thread.cc

@@ -77,6 +77,7 @@ GpuChildThread::~GpuChildThread() {
 }
 
 void GpuChildThread::Shutdown() {
+  ChildThread::Shutdown();
   logging::SetLogMessageHandler(NULL);
 }
 

content/plugin/plugin_thread.cc

@@ -139,6 +139,8 @@ void PluginThread::SetForcefullyTerminatePluginProcess() {
 }
 
 void PluginThread::Shutdown() {
+  ChildThread::Shutdown();
+
   if (preloaded_plugin_module_) {
     base::UnloadNativeLibrary(preloaded_plugin_module_);
     preloaded_plugin_module_ = NULL;

content/renderer/render_thread_impl.cc

@@ -433,6 +433,8 @@ void RenderThreadImpl::Shutdown() {
   FOR_EACH_OBSERVER(
       RenderProcessObserver, observers_, OnRenderProcessShutdown());
 
+  ChildThread::Shutdown();
+
   // Wait for all databases to be closed.
   if (web_database_observer_impl_)
     web_database_observer_impl_->WaitForAllDatabasesToClose();

content/utility/utility_thread_impl.cc

@@ -52,6 +52,8 @@ UtilityThreadImpl::~UtilityThreadImpl() {
 }
 
 void UtilityThreadImpl::Shutdown() {
+  ChildThread::Shutdown();
+
   if (!single_process_)
     WebKit::shutdown();
 }

content/worker/worker_thread.cc

@@ -58,6 +58,8 @@ WorkerThread::~WorkerThread() {
 }
 
 void WorkerThread::Shutdown() {
+  ChildThread::Shutdown();
+
   // Shutdown in reverse of the initialization order.
   channel()->RemoveFilter(indexed_db_message_filter_.get());
   indexed_db_message_filter_ = NULL;