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 87243e716262b31c49a2bf18fc3b3b8c38b29c53..76d5e9f82d8db1c2212db79fb2116a2a1695b0d1 100644
--- a/chrome/renderer/chrome_content_renderer_client.cc
+++ b/chrome/renderer/chrome_content_renderer_client.cc
@@ -1281,6 +1281,25 @@ bool ChromeContentRendererClient::AllowPopup() {
 #endif
 }
 
+bool ChromeContentRendererClient::ShouldFork(WebLocalFrame* frame,
+                                             const GURL& url,
+                                             const std::string& http_method,
+                                             bool is_initial_navigation,
+                                             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 04d63a82dde7b1ec4259ec90e0733f3536e97ad0..e335dfbfabe643d15e78c691750aed3aab4a006a 100644
--- a/chrome/renderer/chrome_content_renderer_client.h
+++ b/chrome/renderer/chrome_content_renderer_client.h
@@ -127,6 +127,11 @@ 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_initial_navigation,
+                bool is_server_redirect) override;
   void WillSendRequest(blink::WebLocalFrame* frame,
                        ui::PageTransition transition_type,
                        const blink::WebURL& url,
diff --git a/content/public/renderer/content_renderer_client.cc b/content/public/renderer/content_renderer_client.cc
index 889362f4bf241c88c7228b7bef029383211ef826..b83f2a91d993e3a086b63c5f01a8960df7f4780f 100644
--- a/content/public/renderer/content_renderer_client.cc
+++ b/content/public/renderer/content_renderer_client.cc
@@ -114,6 +114,14 @@ bool ContentRendererClient::HandleNavigation(
 }
 #endif
 
+bool ContentRendererClient::ShouldFork(blink::WebLocalFrame* frame,
+                                       const GURL& url,
+                                       const std::string& http_method,
+                                       bool is_initial_navigation,
+                                       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 9349a3755f824630904bcd044a6ba403d639f490..5097d3f812f8ad0a583042ba332855c8b3fda222 100644
--- a/content/public/renderer/content_renderer_client.h
+++ b/content/public/renderer/content_renderer_client.h
@@ -229,6 +229,13 @@ 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_initial_navigation,
+                          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. The |force_ignore_site_for_cookies| output parameter
diff --git a/content/renderer/render_frame_impl.cc b/content/renderer/render_frame_impl.cc
index f9e97c36bca9c70af0c585b81902165c1ac6ba5d..f0c50a4693a5363c0b0f834de0e4924e66a39039 100644
--- a/content/renderer/render_frame_impl.cc
+++ b/content/renderer/render_frame_impl.cc
@@ -5755,6 +5755,23 @@ 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.
+      bool is_initial_navigation = render_view_->history_list_length_ == 0;
+      should_fork = GetContentClient()->renderer()->ShouldFork(
+          frame_, url, info->url_request.HttpMethod().Utf8(),
+          is_initial_navigation, false /* is_redirect */);
+    }
+
     if (should_fork) {
       OpenURL(std::move(info));
       return;  // Suppress the load here.