From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Shelley Vohr <shelley.vohr@gmail.com>
Date: Tue, 4 Feb 2020 08:59:32 -0700
Subject: Revert "Remove ContentRendererClient::ShouldFork."

This reverts the CL at https://chromium-review.googlesource.com/c/chromium/src/+/1812128.
We use it to force a new renderer process for navigations, and need to start a new renderer process
for every navigation to keep Node.js working properly. Once Native Modules in the renderer process
are required to be NAPI or context aware (Electron v11), this patch can be removed.

diff --git a/chrome/renderer/chrome_content_renderer_client.cc b/chrome/renderer/chrome_content_renderer_client.cc
index 1aee7c39073ebbcd882d784626c305239e27dffb..00bf1cb692e4692ef1ad27dd26b440224c9c3c8f 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -1300,6 +1300,24 @@ ChromeContentRendererClient::GetProtocolHandlerSecurityLevel() {
 #endif
 }
 
+bool ChromeContentRendererClient::ShouldFork(WebLocalFrame* frame,
+                                             const GURL& url,
+                                             const std::string& http_method,
+                                             bool is_server_redirect) {
+  DCHECK(!frame->Parent());
+
+  // If |url| matches one of the prerendered URLs, stop this navigation and try
+  // to swap in the prerendered page on the browser process. If the prerendered
+  // page no longer exists by the time the OpenURL IPC is handled, a normal
+  // navigation is attempted.
+  if (prerender_dispatcher_.get() &&
+      prerender_dispatcher_->IsPrerenderURL(url)) {
+    return true;
+  }
+
+  return false;
+}
+
 void ChromeContentRendererClient::WillSendRequest(
     WebLocalFrame* frame,
     ui::PageTransition transition_type,
diff --git a/chrome/renderer/chrome_content_renderer_client.h b/chrome/renderer/chrome_content_renderer_client.h
index 4fb3926576c80881a9230bb91bfe7655fec12df1..0f7f3773cf5efcf55cbf001885083f393529911b 100644
--- a/chrome/renderer/chrome_content_renderer_client.h
+++ b/chrome/renderer/chrome_content_renderer_client.h
@@ -121,6 +121,10 @@ class ChromeContentRendererClient
       base::SingleThreadTaskRunner* compositor_thread_task_runner) override;
   bool RunIdleHandlerWhenWidgetsHidden() override;
   bool AllowPopup() override;
+  bool ShouldFork(blink::WebLocalFrame* frame,
+                  const GURL& url,
+                  const std::string& http_method,
+                  bool is_server_redirect) override;
   blink::ProtocolHandlerSecurityLevel GetProtocolHandlerSecurityLevel()
       override;
   void WillSendRequest(blink::WebLocalFrame* frame,
diff --git a/content/public/renderer/content_renderer_client.cc b/content/public/renderer/content_renderer_client.cc
index 5d823d21dc0b8279e449996aa044198ca74a4ac0..d96fa3079022dc444f93b30acd400968dcfcf562 100644
--- a/content/public/renderer/content_renderer_client.cc
+++ b/content/public/renderer/content_renderer_client.cc
@@ -116,6 +116,13 @@ bool ContentRendererClient::HandleNavigation(
 }
 #endif
 
+bool ContentRendererClient::ShouldFork(blink::WebLocalFrame* frame,
+                                       const GURL& url,
+                                       const std::string& http_method,
+                                       bool is_server_redirect) {
+  return false;
+}
+
 void ContentRendererClient::WillSendRequest(
     blink::WebLocalFrame* frame,
     ui::PageTransition transition_type,
diff --git a/content/public/renderer/content_renderer_client.h b/content/public/renderer/content_renderer_client.h
index 6191d4774ae35f00c3b58f62719962de616c8ad7..f717ae1d8e3bf642792f1dcfebbaa2870ff97694 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -206,6 +206,12 @@ class CONTENT_EXPORT ContentRendererClient {
                                 bool is_redirect);
 #endif
 
+  // Returns true if we should fork a new process for the given navigation.
+  virtual bool ShouldFork(blink::WebLocalFrame* frame,
+                          const GURL& url,
+                          const std::string& http_method,
+                          bool is_server_redirect);
+
   // Notifies the embedder that the given frame is requesting the resource at
   // |url|. If the function returns a valid |new_url|, the request must be
   // updated to use it.
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index abcfd464b8a92f65623bc4527123cc75ad38b712..33fe8d118ced62aaba2c81ade206382395630086 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -4924,6 +4924,22 @@ void RenderFrameImpl::BeginNavigation(
     // we can do a per-frame check here rather than a process-wide check.
     bool should_fork = HasWebUIScheme(url) || HasWebUIScheme(old_url) ||
                        (enabled_bindings_ & kWebUIBindingsPolicyMask);
+
+    if (!should_fork && url.SchemeIs(url::kFileScheme)) {
+      // Fork non-file to file opens (see https://crbug.com/1031119).  Note that
+      // this may fork unnecessarily if another tab (hosting a file or not)
+      // targeted this one before its initial navigation, but that shouldn't
+      // cause a problem.
+      should_fork = !old_url.SchemeIs(url::kFileScheme);
+    }
+
+    if (!should_fork) {
+      // Give the embedder a chance.
+      should_fork = GetContentClient()->renderer()->ShouldFork(
+          frame_, url, info->url_request.HttpMethod().Utf8(),
+          false /* is_redirect */);
+    }
+
     if (should_fork) {
       OpenURL(std::move(info));
       return;  // Suppress the load here.