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 eb8968c2a86102d0d3a21f07c394f1c360083c6c..025ef3f70a5ae34faf8c6013fbfba171c7f501ac 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -356,6 +356,11 @@ 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 dbde0706007b8f202fcca5fc05562979617b0183..2adea2c2edabf3c401e9dcd228f1d57c08066059 100644
--- a/content/renderer/renderer_blink_platform_impl.cc
+++ b/content/renderer/renderer_blink_platform_impl.cc
@@ -949,6 +949,12 @@ 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 e7d0d3e7c08c2f6e83726e7fa2557847d148a0ed..c6e0a728150db2b5af41e12304c88d57e51faa43 100644
--- a/content/renderer/renderer_blink_platform_impl.h
+++ b/content/renderer/renderer_blink_platform_impl.h
@@ -208,6 +208,7 @@ 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 0825226fae036b1e5503b66dabe4bd92ad6ee9bb..3cbb1ed9ef65cb9044a76b0a1686f6ab019c87b5 100644
--- a/third_party/blink/public/platform/platform.h
+++ b/third_party/blink/public/platform/platform.h
@@ -714,6 +714,7 @@ 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 68c38d2045c7c23650bd56717081bb001a4e690e..e0e08d4bdf9521ed5c1940d31665d1b675119f0d 100644
--- a/third_party/blink/renderer/core/workers/worker_thread.cc
+++ b/third_party/blink/renderer/core/workers/worker_thread.cc
@@ -732,6 +732,12 @@ 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);