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 dd8f6b9a87a0cc5d2b1ba4867a4cc35ab961a3a2..ef247e62733ebe5058803a4c2a8866af300ba16c 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -403,6 +403,11 @@ 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 daa231edf4ce1890c0a229142504d860d4da443f..929fc1f3de07bdadb8231818e222f914c08a6d3c 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -896,6 +896,12 @@ 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 c1db7661ae79709afcb7a686a792ba0bbafdc59b..1a2ef563c5393ba5e1e2f0ae49b152555587d324 100644
--- a/content/renderer/renderer_blink_platform_impl.h
+++ b/content/renderer/renderer_blink_platform_impl.h
@@ -195,6 +195,7 @@ 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 1131374e07a14bfb4297b2034b669c6b5afe27d1..0f6cf25c6203c4c2bf28b9f4536a153427841502 100644
--- a/third_party/blink/public/platform/platform.h
+++ b/third_party/blink/public/platform/platform.h
@@ -664,6 +664,7 @@ 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 9866cc85f4d2c9d834538010f8b1ca64efc701b9..5af206ddc527f7d7cf44b6c363d2ede08a36ff55 100644
--- a/third_party/blink/renderer/core/workers/worker_thread.cc
+++ b/third_party/blink/renderer/core/workers/worker_thread.cc
@@ -764,6 +764,12 @@ void WorkerThread::PrepareForShutdownOnWorkerThread() {
   }
   pause_handle_.reset();
 
+  {
+    v8::HandleScope handle_scope(GetIsolate());
+    Platform::Current()->WorkerContextWillDestroy(
+        GlobalScope()->ScriptController()->GetContext());
+  }
+
   if (WorkerThreadDebugger* debugger = WorkerThreadDebugger::From(GetIsolate()))
     debugger->WorkerThreadDestroyed(this);