From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Cheng Zhao <zcbenz@gmail.com>
Date: Thu, 20 Sep 2018 17:47:12 -0700
Subject: worker_context_will_destroy.patch

This adds a hook for worker context destruction, which we use in Electron to
shutdown node integration in the worker if relevant.

An attempt to upstream this was made, but rejected:
https://chromium-review.googlesource.com/c/chromium/src/+/1954347

diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index b62158069f9a1ae7141c8f9ef191bd11660797d2..74846c92e2fdfc4dffe9014a010a0acdf9e3017c 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -358,6 +358,11 @@ class CONTENT_EXPORT ContentRendererClient {
   virtual void DidInitializeWorkerContextOnWorkerThread(
       v8::Local<v8::Context> context) {}
 
+  // Notifies that a worker context will be destroyed. This function is called
+  // from the worker thread.
+  virtual void WillDestroyWorkerContextOnWorkerThread(
+      v8::Local<v8::Context> context) {}
+
   // Overwrites the given URL to use an HTML5 embed if possible.
   // An empty URL is returned if the URL is not overriden.
   virtual GURL OverrideFlashEmbedWithHTML(const GURL& url);
diff --git a/content/renderer/renderer_blink_platform_impl.cc b/content/renderer/renderer_blink_platform_impl.cc
index 337c630fc85f33346dccffd51c1fb06db032f1fb..1db3e3674b2b8457f61012565c6103fe1a693929 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -936,6 +936,12 @@ void RendererBlinkPlatformImpl::WillStopWorkerThread() {
   WorkerThreadRegistry::Instance()->WillStopCurrentWorkerThread();
 }
 
+void RendererBlinkPlatformImpl::WorkerContextWillDestroy(
+    const v8::Local<v8::Context>& worker) {
+  GetContentClient()->renderer()->WillDestroyWorkerContextOnWorkerThread(
+      worker);
+}
+
 void RendererBlinkPlatformImpl::WorkerContextCreated(
     const v8::Local<v8::Context>& worker) {
   GetContentClient()->renderer()->DidInitializeWorkerContextOnWorkerThread(
diff --git a/content/renderer/renderer_blink_platform_impl.h b/content/renderer/renderer_blink_platform_impl.h
index b199c34615f0230b46b6128cccfce75d5c2ccc9c..0b8515b4e8cc86f332d4c5c6950bd4656d88fac4 100644
--- a/content/renderer/renderer_blink_platform_impl.h
+++ b/content/renderer/renderer_blink_platform_impl.h
@@ -205,6 +205,7 @@ class CONTENT_EXPORT RendererBlinkPlatformImpl : public BlinkPlatformImpl {
   void DidStartWorkerThread() override;
   void WillStopWorkerThread() override;
   void WorkerContextCreated(const v8::Local<v8::Context>& worker) override;
+  void WorkerContextWillDestroy(const v8::Local<v8::Context>& worker) override;
   bool AllowScriptExtensionForServiceWorker(
       const blink::WebSecurityOrigin& script_origin) override;
   blink::ProtocolHandlerSecurityLevel GetProtocolHandlerSecurityLevel()
diff --git a/third_party/blink/public/platform/platform.h b/third_party/blink/public/platform/platform.h
index f9be3480ae7c96e5a58add277ebce71cbf3b1441..616fd24d928807604fd484a20947e36079affdbe 100644
--- a/third_party/blink/public/platform/platform.h
+++ b/third_party/blink/public/platform/platform.h
@@ -724,6 +724,7 @@ class BLINK_PLATFORM_EXPORT Platform {
   virtual void DidStartWorkerThread() {}
   virtual void WillStopWorkerThread() {}
   virtual void WorkerContextCreated(const v8::Local<v8::Context>& worker) {}
+  virtual void WorkerContextWillDestroy(const v8::Local<v8::Context>& worker) {}
   virtual bool AllowScriptExtensionForServiceWorker(
       const WebSecurityOrigin& script_origin) {
     return false;
diff --git a/third_party/blink/renderer/core/workers/worker_thread.cc b/third_party/blink/renderer/core/workers/worker_thread.cc
index c694aa7cab116003ec4baeb096cc3e386d99019e..1bfc60026d81fa77f120d26d65d9e852afbe1864 100644
--- a/third_party/blink/renderer/core/workers/worker_thread.cc
+++ b/third_party/blink/renderer/core/workers/worker_thread.cc
@@ -717,6 +717,12 @@ void WorkerThread::PrepareForShutdownOnWorkerThread() {
     nested_runner_->QuitNow();
   }
 
+  {
+    v8::HandleScope handle_scope(GetIsolate());
+    Platform::Current()->WorkerContextWillDestroy(
+        GlobalScope()->ScriptController()->GetContext());
+  }
+
   if (WorkerThreadDebugger* debugger = WorkerThreadDebugger::From(GetIsolate()))
     debugger->WorkerThreadDestroyed(this);