refactor: clean up unused parts of the render_frame_host patch file (#28769)

* chore: remove CanUseCustomSiteInstance

* chore: remove unused ShouldOverrideSiteInstanceForNavigation

* chore: remove CreateRelatedSiteInstance

* chore: remove BrowsingInstance::CreateSiteInstanceForURL

* chore: remove NavigationState::REUSE_SITE_INSTANCE

* chore: remove accidentally duplicated code post-patch-clean

* chore: reword patch description for new feature-set

* chore: remove ShouldForceNewSiteInstance and all its unused helpers

patches/chromium/frame_host_manager.patch

@@ -3,195 +3,13 @@ From: deepak1556 <hop2deep@gmail.com>
 Date: Mon, 3 Jun 2019 14:20:05 -0700
 Subject: frame_host_manager.patch
 
-Allows embedder to intercept site instances chosen by chromium
+Allows embedder to intercept site instances created by chromium.
-and respond with custom instance. Also allows for us to at-runtime
-enable or disable this patch.
 
-diff --git a/content/browser/browsing_instance.cc b/content/browser/browsing_instance.cc
-index 30e374aeba7aceacdb58add9c79cb46c6b93af4d..3e34643c4e1d5561c6c7b01e3de8cdd46910afb0 100644
---- a/content/browser/browsing_instance.cc
-+++ b/content/browser/browsing_instance.cc
-@@ -61,6 +61,13 @@ scoped_refptr<SiteInstanceImpl> BrowsingInstance::GetSiteInstanceForURL(
-   return instance;
- }
- 
-+scoped_refptr<SiteInstanceImpl> BrowsingInstance::CreateSiteInstanceForURL(
-+    const GURL& url) {
-+  scoped_refptr<SiteInstanceImpl> instance = new SiteInstanceImpl(this);
-+  instance->SetSite(UrlInfo(url, UrlInfo::OriginIsolationRequest::kNone));
-+  return instance;
-+}
-+
- SiteInfo BrowsingInstance::GetSiteInfoForURL(const UrlInfo& url_info,
-                                              bool allow_default_instance) {
-   scoped_refptr<SiteInstanceImpl> site_instance =
-diff --git a/content/browser/browsing_instance.h b/content/browser/browsing_instance.h
-index f426d1ebdaa9d13c7e47f22ce617e2b61a862854..26907541dd4268e3f8c82676bdda892bd1ed04e7 100644
---- a/content/browser/browsing_instance.h
-+++ b/content/browser/browsing_instance.h
-@@ -151,6 +151,11 @@ class CONTENT_EXPORT BrowsingInstance final
-       const UrlInfo& url_info,
-       bool allow_default_instance);
- 
-+  // Create a new SiteInstance for the given URL bound the current
-+  // BrowsingInstance.
-+  scoped_refptr<SiteInstanceImpl> CreateSiteInstanceForURL(
-+      const GURL& url);
-+
-   // Adds the given SiteInstance to our map, to ensure that we do not create
-   // another SiteInstance for the same site.
-   void RegisterSiteInstance(SiteInstanceImpl* site_instance);
-diff --git a/content/browser/renderer_host/navigation_request.cc b/content/browser/renderer_host/navigation_request.cc
-index 1f0b01cbf17267bd8c03deb4a28938566f7033ef..5ccf84c2b847e9d2cbc97f4b2390220324a807c3 100644
---- a/content/browser/renderer_host/navigation_request.cc
-+++ b/content/browser/renderer_host/navigation_request.cc
-@@ -1572,6 +1572,21 @@ void NavigationRequest::BeginNavigation() {
-     if (IsSameDocument()) {
-       render_frame_host_ = frame_tree_node_->current_frame_host();
-     } else {
-+      // In Electron, a new process is started for every navigation when node is
-+      // integrated in the renderer. Since GetFrameHostForNavigation is called more
-+      // than once per navigation, we want to return the same frame host once
-+      // the response has started, otherwise if the frame host that started the response
-+      // and the frame host that is available for commit don't match then request will
-+      // be cancelled. We rely on the NavigationRequest::state_ to determine this
-+      // factor
-+      //
-+      // bool has_response_started =
-+      //    (request->state() >= NavigationRequest::WILL_PROCESS_RESPONSE &&
-+      //     !speculative_render_frame_host_);
-+      //
-+      // Hence this call is necesary before the call to GetFrameHostForNavigation.
-+      SetState(REUSE_SITE_INSTANCE);
-+
-       // Select an appropriate RenderFrameHost.
-       std::string frame_host_choice_reason;
-       render_frame_host_ =
-@@ -6152,6 +6167,7 @@ void NavigationRequest::CheckStateTransition(NavigationState state) const {
-           {WILL_START_REQUEST, {
-               WILL_REDIRECT_REQUEST,
-               WILL_PROCESS_RESPONSE,
-+              REUSE_SITE_INSTANCE,
-               READY_TO_COMMIT,
-               DID_COMMIT,
-               CANCELING,
-@@ -6165,10 +6181,15 @@ void NavigationRequest::CheckStateTransition(NavigationState state) const {
-               WILL_FAIL_REQUEST,
-           }},
-           {WILL_PROCESS_RESPONSE, {
-+              REUSE_SITE_INSTANCE,
-               READY_TO_COMMIT,
-               CANCELING,
-               WILL_FAIL_REQUEST,
-           }},
-+          {REUSE_SITE_INSTANCE, {
-+              WILL_PROCESS_RESPONSE,
-+              READY_TO_COMMIT,
-+          }},
-           {READY_TO_COMMIT, {
-               NOT_STARTED,
-               DID_COMMIT,
-diff --git a/content/browser/renderer_host/navigation_request.h b/content/browser/renderer_host/navigation_request.h
-index 304de734c34efd3c4f6ab561d66ecf7d655387f8..6817bfd0ea8934b2b1a1d62415b5475d5c88d20b 100644
---- a/content/browser/renderer_host/navigation_request.h
-+++ b/content/browser/renderer_host/navigation_request.h
-@@ -140,6 +140,10 @@ class CONTENT_EXPORT NavigationRequest
-     // asynchronous.
-     WILL_PROCESS_RESPONSE,
- 
-+    // Electron: state that is between than WILL_PROCESS_RESPONSE and
-+    // READY_TO_COMMIT to force reuse the same site instance.
-+    REUSE_SITE_INSTANCE,
-+
-     // The response started on the IO thread and is ready to be committed.
-     READY_TO_COMMIT,
- 
 diff --git a/content/browser/renderer_host/render_frame_host_manager.cc b/content/browser/renderer_host/render_frame_host_manager.cc
-index af497e6916d72bfbd40fe9f131be6022482ef810..74f9fe3a0a0de20d48bc8b2d397109381ea66481 100644
+index af497e6916d72bfbd40fe9f131be6022482ef810..a5411ead9c465dab2814ebb25836d10e2e8cd494 100644
 --- a/content/browser/renderer_host/render_frame_host_manager.cc
 +++ b/content/browser/renderer_host/render_frame_host_manager.cc
-@@ -2859,6 +2859,16 @@ scoped_refptr<SiteInstance>
+@@ -2922,6 +2922,9 @@ RenderFrameHostManager::GetSiteInstanceForNavigationRequest(
- RenderFrameHostManager::GetSiteInstanceForNavigationRequest(
-     NavigationRequest* request,
-     std::string* reason) {
-+  // Compute the SiteInstance that the navigation should use, which will be
-+  // either the current SiteInstance or a new one.
-+  //
-+  // TODO(clamy): We should also consider as a candidate SiteInstance the
-+  // speculative SiteInstance that was computed on redirects.
-+  SiteInstanceImpl* candidate_site_instance =
-+      speculative_render_frame_host_
-+          ? speculative_render_frame_host_->GetSiteInstance()
-+          : nullptr;
-+
-   SiteInstance* current_site_instance = render_frame_host_->GetSiteInstance();
- 
-   // All children of MHTML documents must be MHTML documents. They all live in
-@@ -2886,10 +2896,59 @@ RenderFrameHostManager::GetSiteInstanceForNavigationRequest(
-   //
-   // TODO(clamy): We should also consider as a candidate SiteInstance the
-   // speculative SiteInstance that was computed on redirects.
--  SiteInstanceImpl* candidate_site_instance =
--      speculative_render_frame_host_
--          ? speculative_render_frame_host_->GetSiteInstance()
--          : nullptr;
-+  if (!GetContentClient()->browser()->CanUseCustomSiteInstance() &&
-+      frame_tree_node_->IsMainFrame()) {
-+    BrowserContext* browser_context = GetNavigationController().GetBrowserContext();
-+    bool has_navigation_started = request->state() != NavigationRequest::NOT_STARTED;
-+    bool has_response_started =
-+        (request->state() >= NavigationRequest::WILL_PROCESS_RESPONSE &&
-+         !speculative_render_frame_host_);
-+    // Gives user a chance to choose a custom site instance.
-+    SiteInstance* affinity_site_instance = nullptr;
-+    scoped_refptr<SiteInstance> overriden_site_instance;
-+    bool should_register_site_instance = false;
-+    ContentBrowserClient::SiteInstanceForNavigationType siteInstanceType =
-+        GetContentClient()->browser()->ShouldOverrideSiteInstanceForNavigation(
-+            current_frame_host(), speculative_frame_host(), browser_context,
-+            request->common_params().url, has_navigation_started,
-+            has_response_started, &affinity_site_instance);
-+    switch (siteInstanceType) {
-+      case ContentBrowserClient::SiteInstanceForNavigationType::
-+          FORCE_CANDIDATE_OR_NEW:
-+        overriden_site_instance =
-+            candidate_site_instance
-+                ? candidate_site_instance
-+                : current_site_instance->CreateRelatedSiteInstance(
-+                                            request->common_params().url);
-+        should_register_site_instance = true;
-+        break;
-+      case ContentBrowserClient::SiteInstanceForNavigationType::FORCE_NEW:
-+        overriden_site_instance = current_site_instance->CreateRelatedSiteInstance(
-+            request->common_params().url);
-+        should_register_site_instance = true;
-+        break;
-+      case ContentBrowserClient::SiteInstanceForNavigationType::FORCE_CURRENT:
-+        overriden_site_instance = render_frame_host_->GetSiteInstance();
-+        break;
-+      case ContentBrowserClient::SiteInstanceForNavigationType::FORCE_AFFINITY:
-+        DCHECK(affinity_site_instance);
-+        overriden_site_instance =
-+            scoped_refptr<SiteInstance>(affinity_site_instance);
-+        break;
-+      case ContentBrowserClient::SiteInstanceForNavigationType::ASK_CHROMIUM:
-+        DCHECK(!affinity_site_instance);
-+        break;
-+      default:
-+        break;
-+    }
-+    if (overriden_site_instance) {
-+      if (should_register_site_instance) {
-+        GetContentClient()->browser()->RegisterPendingSiteInstance(
-+            render_frame_host_.get(), overriden_site_instance.get());
-+      }
-+      return overriden_site_instance;
-+    }
-+  }
- 
-   // Account for renderer-initiated reload as well.
-   // Needed as a workaround for https://crbug.com/1045524, remove it when it is
-@@ -2922,6 +2981,9 @@ RenderFrameHostManager::GetSiteInstanceForNavigationRequest(
      request->ResetStateForSiteInstanceChange();
    }
  
@@ -201,101 +19,14 @@ index af497e6916d72bfbd40fe9f131be6022482ef810..74f9fe3a0a0de20d48bc8b2d39710938
    return dest_site_instance;
  }
  
-diff --git a/content/browser/site_instance_impl.cc b/content/browser/site_instance_impl.cc
-index 8013a8606e4f01ef63b7b546fd7537f9232648c3..2f74a84667d7cf760642fb1577f22ad85ca00ecd 100644
---- a/content/browser/site_instance_impl.cc
-+++ b/content/browser/site_instance_impl.cc
-@@ -1135,6 +1135,10 @@ bool SiteInstanceImpl::HasRelatedSiteInstance(const SiteInfo& site_info) {
-   return browsing_instance_->HasSiteInstance(site_info);
- }
- 
-+scoped_refptr<SiteInstance> SiteInstanceImpl::CreateRelatedSiteInstance(const GURL& url) {
-+  return browsing_instance_->CreateSiteInstanceForURL(url);
-+}
-+
- scoped_refptr<SiteInstance> SiteInstanceImpl::GetRelatedSiteInstance(
-     const GURL& url) {
-   return GetRelatedSiteInstanceImpl(
-diff --git a/content/browser/site_instance_impl.h b/content/browser/site_instance_impl.h
-index 40c314243ae5aa8540ce6528273ee2f0b7f0aca1..dce5cf6cde036d35c1b78b8fa768617628d380c2 100644
---- a/content/browser/site_instance_impl.h
-+++ b/content/browser/site_instance_impl.h
-@@ -501,6 +501,7 @@ class CONTENT_EXPORT SiteInstanceImpl final : public SiteInstance,
-   BrowserContext* GetBrowserContext() override;
-   const GURL& GetSiteURL() override;
-   scoped_refptr<SiteInstance> GetRelatedSiteInstance(const GURL& url) override;
-+  scoped_refptr<SiteInstance> CreateRelatedSiteInstance(const GURL& url) override;
-   bool IsRelatedSiteInstance(const SiteInstance* instance) override;
-   size_t GetRelatedActiveContentsCount() override;
-   bool RequiresDedicatedProcess() override;
-diff --git a/content/public/browser/content_browser_client.cc b/content/public/browser/content_browser_client.cc
-index 0d2eba4321ece3e9cfb2b16dead343dd51672714..45fe96cb01e4d6e2772f1304eb1c5ac274c4f713 100644
---- a/content/public/browser/content_browser_client.cc
-+++ b/content/public/browser/content_browser_client.cc
-@@ -72,6 +72,21 @@
- 
- namespace content {
- 
-+bool ContentBrowserClient::CanUseCustomSiteInstance() {
-+  return false;
-+}
-+
-+ContentBrowserClient::SiteInstanceForNavigationType ContentBrowserClient::ShouldOverrideSiteInstanceForNavigation(
-+    content::RenderFrameHost* current_rfh,
-+    content::RenderFrameHost* speculative_rfh,
-+    content::BrowserContext* browser_context,
-+    const GURL& url,
-+    bool has_navigation_started,
-+    bool has_request_started,
-+    content::SiteInstance** affinity_site_instance) const {
-+  return SiteInstanceForNavigationType::ASK_CHROMIUM;
-+}
-+
- std::unique_ptr<BrowserMainParts> ContentBrowserClient::CreateBrowserMainParts(
-     const MainFunctionParams& parameters) {
-   return nullptr;
 diff --git a/content/public/browser/content_browser_client.h b/content/public/browser/content_browser_client.h
-index 47befa844ca54f463b627864827aa670454dfed4..010a63958d094f65b0f1838888991ecd6679b086 100644
+index 47befa844ca54f463b627864827aa670454dfed4..1a27f50e5922c3886816e7523dda98e1d7a87bda 100644
 --- a/content/public/browser/content_browser_client.h
 +++ b/content/public/browser/content_browser_client.h
-@@ -261,8 +261,45 @@ class CONTENT_EXPORT ContentBrowserClient {
+@@ -263,6 +263,11 @@ class CONTENT_EXPORT ContentBrowserClient {
-   using IsClipboardPasteContentAllowedCallback =
-       base::OnceCallback<void(ClipboardPasteContentAllowed)>;
  
-+  // Identifies the type of site instance to use for a navigation.
-+  enum SiteInstanceForNavigationType {
-+    // Use either the candidate site instance or, if it doesn't exist
-+    // a new, unrelated site instance for the navigation.
-+    FORCE_CANDIDATE_OR_NEW = 0,
-+
-+    // Use the current site instance for the navigation.
-+    FORCE_CURRENT,
-+
-+    // Use a new, unrelated site instance.
-+    FORCE_NEW,
-+
-+    // Use the provided affinity site instance for the navigation.
-+    FORCE_AFFINITY,
-+
-+    // Delegate the site instance creation to Chromium.
-+    ASK_CHROMIUM
-+  };
-+
    virtual ~ContentBrowserClient() = default;
  
-+  // Electron: Allows disabling the below ShouldOverride patch
-+  virtual bool CanUseCustomSiteInstance();
-+
-+  // Electron: Allows overriding the SiteInstance when navigating.
-+  virtual SiteInstanceForNavigationType ShouldOverrideSiteInstanceForNavigation(
-+      content::RenderFrameHost* current_rfh,
-+      content::RenderFrameHost* speculative_rfh,
-+      content::BrowserContext* browser_context,
-+      const GURL& url,
-+      bool has_navigation_started,
-+      bool has_request_started,
-+      content::SiteInstance** affinity_site_instance) const;
-+
 +  // Electron: Registers a pending site instance during a navigation.
 +  virtual void RegisterPendingSiteInstance(
 +      content::RenderFrameHost* rfh,
@@ -304,19 +35,3 @@ index 47befa844ca54f463b627864827aa670454dfed4..010a63958d094f65b0f1838888991ecd
    // Allows the embedder to set any number of custom BrowserMainParts
    // implementations for the browser startup code. See comments in
    // browser_main_parts.h.
-diff --git a/content/public/browser/site_instance.h b/content/public/browser/site_instance.h
-index 9b90d52cac2b6a0d15e1ec1f562f0e376ce6be7c..5bc69adfab68c45528ba8d5e81b03b3f6db934a7 100644
---- a/content/public/browser/site_instance.h
-+++ b/content/public/browser/site_instance.h
-@@ -135,6 +135,11 @@ class CONTENT_EXPORT SiteInstance : public base::RefCounted<SiteInstance> {
-   //   corresponds to a site URL with the host "example.com".
-   virtual const GURL& GetSiteURL() = 0;
- 
-+  // Create a SiteInstance for the given URL that shares the current
-+  // BrowsingInstance.
-+  virtual scoped_refptr<SiteInstance> CreateRelatedSiteInstance(
-+    const GURL& url) = 0;
-+
-   // Gets a SiteInstance for the given URL that shares the current
-   // BrowsingInstance, creating a new SiteInstance if necessary.  This ensures
-   // that a BrowsingInstance only has one SiteInstance per site, so that pages

shell/browser/electron_browser_client.cc

@@ -193,29 +193,6 @@ namespace electron {
 
 namespace {
 
-// Next navigation should not restart renderer process.
-bool g_suppress_renderer_process_restart = false;
-
-// c.f. https://chromium-review.googlesource.com/c/chromium/src/+/2680274
-content::SiteInfo GetSiteForURL(content::BrowserContext* browser_context,
-                                const GURL& url) {
-  return content::SiteInfo::Create(
-      content::IsolationContext(browser_context),
-      content::UrlInfo(url, content::UrlInfo::OriginIsolationRequest::kNone),
-      content::CoopCoepCrossOriginIsolatedInfo::CreateNonIsolated());
-}
-
-bool IsSameWebSite(content::BrowserContext* browser_context,
-                   content::SiteInstance* site_instance,
-                   const GURL& dest_url) {
-  return site_instance->IsSameSiteWithURL(dest_url) ||
-         // `IsSameSiteWithURL` doesn't seem to work for some URIs such as
-         // `file:`, handle these scenarios by comparing only the site as
-         // defined by `GetSiteForURL`.
-         (GetSiteForURL(browser_context, dest_url).site_url() ==
-          site_instance->GetSiteURL());
-}
-
 ElectronBrowserClient* g_browser_client = nullptr;
 
 base::LazyInstance<std::string>::DestructorAtExit
@@ -391,70 +368,6 @@ content::WebContents* ElectronBrowserClient::GetWebContentsFromProcessID(
   return WebContentsPreferences::GetWebContentsFromProcessID(process_id);
 }
 
-bool ElectronBrowserClient::ShouldForceNewSiteInstance(
-    content::RenderFrameHost* current_rfh,
-    content::RenderFrameHost* speculative_rfh,
-    content::BrowserContext* browser_context,
-    const GURL& url,
-    bool has_response_started) const {
-  if (url.SchemeIs(url::kJavaScriptScheme))
-    // "javascript:" scheme should always use same SiteInstance
-    return false;
-  if (url.SchemeIs(extensions::kExtensionScheme))
-    return false;
-
-  content::SiteInstance* current_instance = current_rfh->GetSiteInstance();
-  content::SiteInstance* speculative_instance =
-      speculative_rfh ? speculative_rfh->GetSiteInstance() : nullptr;
-  int process_id = current_instance->GetProcess()->GetID();
-  if (NavigationWasRedirectedCrossSite(browser_context, current_instance,
-                                       speculative_instance, url,
-                                       has_response_started)) {
-    // Navigation was redirected. We can't force the current, speculative or a
-    // new unrelated site instance to be used. Delegate to the content layer.
-    return false;
-  } else if (IsRendererSandboxed(process_id)) {
-    // Renderer is sandboxed, delegate the decision to the content layer for all
-    // origins.
-    return false;
-  } else if (!RendererUsesNativeWindowOpen(process_id)) {
-    // non-sandboxed renderers without native window.open should always create
-    // a new SiteInstance
-    return true;
-  } else {
-    auto* web_contents = content::WebContents::FromRenderFrameHost(current_rfh);
-    if (!ChildWebContentsTracker::FromWebContents(web_contents)) {
-      // Root WebContents should always create new process to make sure
-      // native addons are loaded correctly after reload / navigation.
-      // (Non-root WebContents opened by window.open() should try to
-      //  reuse process to allow synchronous cross-window scripting.)
-      return true;
-    }
-  }
-
-  // Create new a SiteInstance if navigating to a different site.
-  return !IsSameWebSite(browser_context, current_instance, url);
-}
-
-bool ElectronBrowserClient::NavigationWasRedirectedCrossSite(
-    content::BrowserContext* browser_context,
-    content::SiteInstance* current_instance,
-    content::SiteInstance* speculative_instance,
-    const GURL& dest_url,
-    bool has_response_started) const {
-  bool navigation_was_redirected = false;
-  if (has_response_started) {
-    navigation_was_redirected =
-        !IsSameWebSite(browser_context, current_instance, dest_url);
-  } else {
-    navigation_was_redirected =
-        speculative_instance &&
-        !IsSameWebSite(browser_context, speculative_instance, dest_url);
-  }
-
-  return navigation_was_redirected;
-}
-
 void ElectronBrowserClient::AddProcessPreferences(
     int process_id,
     ElectronBrowserClient::ProcessPreferences prefs) {
@@ -469,11 +382,6 @@ bool ElectronBrowserClient::IsProcessObserved(int process_id) const {
   return process_preferences_.find(process_id) != process_preferences_.end();
 }
 
-bool ElectronBrowserClient::IsRendererSandboxed(int process_id) const {
-  auto it = process_preferences_.find(process_id);
-  return it != process_preferences_.end() && it->second.sandbox;
-}
-
 bool ElectronBrowserClient::RendererUsesNativeWindowOpen(int process_id) const {
   auto it = process_preferences_.find(process_id);
   return it != process_preferences_.end() && it->second.native_window_open;
@@ -586,57 +494,6 @@ void ElectronBrowserClient::OverrideWebkitPrefs(
   }
 }
 
-content::ContentBrowserClient::SiteInstanceForNavigationType
-ElectronBrowserClient::ShouldOverrideSiteInstanceForNavigation(
-    content::RenderFrameHost* current_rfh,
-    content::RenderFrameHost* speculative_rfh,
-    content::BrowserContext* browser_context,
-    const GURL& url,
-    bool has_navigation_started,
-    bool has_response_started,
-    content::SiteInstance** affinity_site_instance) const {
-  if (g_suppress_renderer_process_restart) {
-    g_suppress_renderer_process_restart = false;
-    return SiteInstanceForNavigationType::ASK_CHROMIUM;
-  }
-
-  // Do we have an affinity site to manage ?
-  content::SiteInstance* site_instance_from_affinity =
-      GetSiteInstanceFromAffinity(browser_context, url, current_rfh);
-  if (site_instance_from_affinity) {
-    *affinity_site_instance = site_instance_from_affinity;
-    return SiteInstanceForNavigationType::FORCE_AFFINITY;
-  }
-
-  if (!ShouldForceNewSiteInstance(current_rfh, speculative_rfh, browser_context,
-                                  url, has_response_started)) {
-    return SiteInstanceForNavigationType::ASK_CHROMIUM;
-  }
-
-  // ShouldOverrideSiteInstanceForNavigation will be called more than once
-  // during a navigation (currently twice, on request and when it's about
-  // to commit in the renderer), look at
-  // RenderFrameHostManager::GetFrameHostForNavigation.
-  // In the default mode we should reuse the same site instance until the
-  // request commits otherwise it will get destroyed. Currently there is no
-  // unique lifetime tracker for a navigation request during site instance
-  // creation. We check for the state of the request, which should be one of
-  // (WAITING_FOR_RENDERER_RESPONSE, STARTED, RESPONSE_STARTED, FAILED) along
-  // with the availability of a speculative render frame host.
-  if (has_response_started) {
-    return SiteInstanceForNavigationType::FORCE_CURRENT;
-  }
-
-  if (!has_navigation_started) {
-    // If the navigation didn't start yet, ignore any candidate site instance.
-    // If such instance exists, it belongs to a previous navigation still
-    // taking place. Fixes https://github.com/electron/electron/issues/17576.
-    return SiteInstanceForNavigationType::FORCE_NEW;
-  }
-
-  return SiteInstanceForNavigationType::FORCE_CANDIDATE_OR_NEW;
-}
-
 void ElectronBrowserClient::RegisterPendingSiteInstance(
     content::RenderFrameHost* rfh,
     content::SiteInstance* pending_site_instance) {
@@ -1735,10 +1592,6 @@ ElectronBrowserClient::GetPluginMimeTypesWithExternalHandlers(
   return mime_types;
 }
 
-bool ElectronBrowserClient::CanUseCustomSiteInstance() {
-  return true;
-}
-
 content::SerialDelegate* ElectronBrowserClient::GetSerialDelegate() {
   if (!serial_delegate_)
     serial_delegate_ = std::make_unique<ElectronSerialDelegate>();

shell/browser/electron_browser_client.h

@@ -85,7 +85,6 @@ class ElectronBrowserClient : public content::ContentBrowserClient,
   void SetUserAgent(const std::string& user_agent);
 
   content::SerialDelegate* GetSerialDelegate() override;
-  bool CanUseCustomSiteInstance() override;
 
   content::BluetoothDelegate* GetBluetoothDelegate() override;
 
@@ -97,14 +96,6 @@ class ElectronBrowserClient : public content::ContentBrowserClient,
 
   void OverrideWebkitPrefs(content::WebContents* web_contents,
                            blink::web_pref::WebPreferences* prefs) override;
-  SiteInstanceForNavigationType ShouldOverrideSiteInstanceForNavigation(
-      content::RenderFrameHost* current_rfh,
-      content::RenderFrameHost* speculative_rfh,
-      content::BrowserContext* browser_context,
-      const GURL& url,
-      bool has_navigation_started,
-      bool has_response_started,
-      content::SiteInstance** affinity_site_instance) const override;
   void RegisterPendingSiteInstance(
       content::RenderFrameHost* render_frame_host,
       content::SiteInstance* pending_site_instance) override;
@@ -289,21 +280,9 @@ class ElectronBrowserClient : public content::ContentBrowserClient,
     content::BrowserContext* browser_context = nullptr;
   };
 
-  bool ShouldForceNewSiteInstance(content::RenderFrameHost* current_rfh,
-                                  content::RenderFrameHost* speculative_rfh,
-                                  content::BrowserContext* browser_context,
-                                  const GURL& dest_url,
-                                  bool has_response_started) const;
-  bool NavigationWasRedirectedCrossSite(
-      content::BrowserContext* browser_context,
-      content::SiteInstance* current_instance,
-      content::SiteInstance* speculative_instance,
-      const GURL& dest_url,
-      bool has_response_started) const;
   void AddProcessPreferences(int process_id, ProcessPreferences prefs);
   void RemoveProcessPreferences(int process_id);
   bool IsProcessObserved(int process_id) const;
-  bool IsRendererSandboxed(int process_id) const;
   bool RendererUsesNativeWindowOpen(int process_id) const;
   bool RendererDisablesPopups(int process_id) const;
   content::SiteInstance* GetSiteInstanceFromAffinity(