Forcibly clear worker ref counts on shutdown.

content/browser/renderer_host/render_process_host_impl.h

Index: content/browser/renderer_host/render_process_host_impl.h
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index c937f7b0dda72b565b6a75eff8d1db556fdfb29f..2c77e188857e607af5e4b3a16abe4f8b3f17e609 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -181,6 +181,8 @@ class CONTENT_EXPORT RenderProcessHostImpl
   void DecrementServiceWorkerRefCount() override;
   void IncrementSharedWorkerRefCount() override;
   void DecrementSharedWorkerRefCount() override;
+  void ForceReleaseWorkerRefCounts() override;
+  bool IsWorkerRefCountDisabled() override;
   void PurgeAndSuspend() override;
 
   mojom::RouteProvider* GetRemoteRouteProvider();
@@ -438,6 +440,10 @@ class CONTENT_EXPORT RenderProcessHostImpl
   size_t service_worker_ref_count_;
   size_t shared_worker_ref_count_;
 
+  // Set in ForceReleaseWorkerRefCounts. When true, worker ref counts must no
+  // longer be modified.
+  bool is_worker_ref_count_disabled_;
+
   // The registered IPC listener objects. When this list is empty, we should
   // delete ourselves.
   IDMap<IPC::Listener> listeners_;