diff --git chrome/browser/plugins/plugin_info_host_impl.cc chrome/browser/plugins/plugin_info_host_impl.cc
index 7ceb1d7b854d9..5efcb8c09058c 100644
--- chrome/browser/plugins/plugin_info_host_impl.cc
+++ chrome/browser/plugins/plugin_info_host_impl.cc
@@ -16,6 +16,7 @@
 #include "base/strings/utf_string_conversions.h"
 #include "build/branding_buildflags.h"
 #include "build/build_config.h"
+#include "cef/libcef/features/runtime.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/content_settings/host_content_settings_map_factory.h"
 #include "chrome/browser/plugins/chrome_plugin_service_filter.h"
@@ -50,6 +51,10 @@
 #include "url/gurl.h"
 #include "url/origin.h"
 
+#if BUILDFLAG(ENABLE_CEF)
+#include "cef/libcef/common/extensions/extensions_util.h"
+#endif
+
 #if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "components/guest_view/browser/guest_view_base.h"
 #include "extensions/browser/extension_registry.h"
@@ -135,6 +140,9 @@ bool IsPluginLoadingAccessibleResourceInWebView(
     extensions::ExtensionRegistry* extension_registry,
     int process_id,
     const GURL& resource) {
+  if (!extension_registry)
+    return false;
+
   extensions::WebViewRendererState* renderer_state =
       extensions::WebViewRendererState::GetInstance();
   std::string partition_id;
@@ -163,14 +171,18 @@ bool IsPluginLoadingAccessibleResourceInWebView(
 
 PluginInfoHostImpl::Context::Context(int render_process_id, Profile* profile)
     : render_process_id_(render_process_id),
-#if BUILDFLAG(ENABLE_EXTENSIONS)
-      extension_registry_(extensions::ExtensionRegistry::Get(profile)),
-#endif
       host_content_settings_map_(
           HostContentSettingsMapFactory::GetForProfile(profile)),
       plugin_prefs_(PluginPrefs::GetForProfile(profile)) {
   allow_outdated_plugins_.Init(prefs::kPluginsAllowOutdated,
                                profile->GetPrefs());
+
+#if BUILDFLAG(ENABLE_EXTENSIONS)
+#if BUILDFLAG(ENABLE_CEF)
+  if (!cef::IsAlloyRuntimeEnabled() || extensions::ExtensionsEnabled())
+#endif
+    extension_registry_ = extensions::ExtensionRegistry::Get(profile);
+#endif
 }
 
 PluginInfoHostImpl::Context::~Context() {}
diff --git chrome/browser/plugins/plugin_utils.cc chrome/browser/plugins/plugin_utils.cc
index 8b3f569882aeb..ae0c4aa9a0514 100644
--- chrome/browser/plugins/plugin_utils.cc
+++ chrome/browser/plugins/plugin_utils.cc
@@ -5,6 +5,7 @@
 #include "chrome/browser/plugins/plugin_utils.h"
 
 #include "base/values.h"
+#include "cef/libcef/features/runtime.h"
 #include "chrome/browser/profiles/profile.h"
 #include "components/content_settings/core/browser/host_content_settings_map.h"
 #include "components/content_settings/core/common/content_settings_types.h"
@@ -14,6 +15,10 @@
 #include "url/gurl.h"
 #include "url/origin.h"
 
+#if BUILDFLAG(ENABLE_CEF)
+#include "cef/libcef/common/extensions/extensions_util.h"
+#endif
+
 #if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "chrome/browser/extensions/chrome_content_browser_client_extensions_part.h"
 #include "chrome/common/pref_names.h"
@@ -69,6 +74,12 @@ base::flat_map<std::string, std::string>
 PluginUtils::GetMimeTypeToExtensionIdMap(
     content::BrowserContext* browser_context) {
   base::flat_map<std::string, std::string> mime_type_to_extension_id_map;
+
+#if BUILDFLAG(ENABLE_CEF)
+  if (cef::IsAlloyRuntimeEnabled() && !extensions::ExtensionsEnabled())
+    return mime_type_to_extension_id_map;
+#endif
+
 #if BUILDFLAG(ENABLE_EXTENSIONS)
   Profile* profile = Profile::FromBrowserContext(browser_context);
   if (extensions::ChromeContentBrowserClientExtensionsPart::
diff --git chrome/common/google_url_loader_throttle.cc chrome/common/google_url_loader_throttle.cc
index a29a2739af3c8..0feb1a87cef64 100644
--- chrome/common/google_url_loader_throttle.cc
+++ chrome/common/google_url_loader_throttle.cc
@@ -7,6 +7,7 @@
 #include "base/feature_list.h"
 #include "base/metrics/histogram_functions.h"
 #include "build/build_config.h"
+#include "cef/libcef/features/runtime.h"
 #include "chrome/common/chrome_features.h"
 #include "chrome/common/net/safe_search_util.h"
 #include "components/google/core/common/google_util.h"
@@ -19,6 +20,10 @@
 #include "ui/base/device_form_factor.h"
 #endif
 
+#if BUILDFLAG(ENABLE_CEF)
+#include "cef/libcef/common/extensions/extensions_util.h"
+#endif
+
 #if BUILDFLAG(ENABLE_EXTENSIONS)
 #include "extensions/common/extension_urls.h"
 #endif
@@ -158,6 +163,11 @@ void GoogleURLLoaderThrottle::WillProcessResponse(
     const GURL& response_url,
     network::mojom::URLResponseHead* response_head,
     bool* defer) {
+#if BUILDFLAG(ENABLE_CEF)
+  if (cef::IsAlloyRuntimeEnabled() && !extensions::ExtensionsEnabled())
+    return;
+#endif
+
   // Built-in additional protection for the chrome web store origin by ensuring
   // that the X-Frame-Options protection mechanism is set to either DENY or
   // SAMEORIGIN.
diff --git chrome/renderer/chrome_content_renderer_client.cc chrome/renderer/chrome_content_renderer_client.cc
index 3d08b706ec4a0..7f4a0398e51f9 100644
--- chrome/renderer/chrome_content_renderer_client.cc
+++ chrome/renderer/chrome_content_renderer_client.cc
@@ -978,6 +978,7 @@ WebPlugin* ChromeContentRendererClient::CreatePlugin(
 
     if ((status == chrome::mojom::PluginStatus::kUnauthorized ||
          status == chrome::mojom::PluginStatus::kBlocked) &&
+        content_settings_agent_delegate &&
         content_settings_agent_delegate->IsPluginTemporarilyAllowed(
             identifier)) {
       status = chrome::mojom::PluginStatus::kAllowed;
@@ -1147,7 +1148,8 @@ WebPlugin* ChromeContentRendererClient::CreatePlugin(
         render_frame->GetRemoteAssociatedInterfaces()->GetInterface(
             plugin_auth_host.BindNewEndpointAndPassReceiver());
         plugin_auth_host->BlockedUnauthorizedPlugin(group_name, identifier);
-        content_settings_agent->DidBlockContentType(content_type);
+        if (content_settings_agent)
+          content_settings_agent->DidBlockContentType(content_type);
         break;
       }
       case chrome::mojom::PluginStatus::kBlocked: {
@@ -1156,7 +1158,8 @@ WebPlugin* ChromeContentRendererClient::CreatePlugin(
             l10n_util::GetStringFUTF16(IDS_PLUGIN_BLOCKED, group_name));
         placeholder->AllowLoading();
         RenderThread::Get()->RecordAction(UserMetricsAction("Plugin_Blocked"));
-        content_settings_agent->DidBlockContentType(content_type);
+        if (content_settings_agent)
+          content_settings_agent->DidBlockContentType(content_type);
         break;
       }
       case chrome::mojom::PluginStatus::kBlockedByPolicy: {
@@ -1166,7 +1169,8 @@ WebPlugin* ChromeContentRendererClient::CreatePlugin(
                                        group_name));
         RenderThread::Get()->RecordAction(
             UserMetricsAction("Plugin_BlockedByPolicy"));
-        content_settings_agent->DidBlockContentType(content_type);
+        if (content_settings_agent)
+          content_settings_agent->DidBlockContentType(content_type);
         break;
       }
     }
diff --git content/browser/browser_plugin/browser_plugin_embedder.h content/browser/browser_plugin/browser_plugin_embedder.h
index ad5f1925735fd..a871f4a7792a7 100644
--- content/browser/browser_plugin/browser_plugin_embedder.h
+++ content/browser/browser_plugin/browser_plugin_embedder.h
@@ -15,6 +15,7 @@
 #define CONTENT_BROWSER_BROWSER_PLUGIN_BROWSER_PLUGIN_EMBEDDER_H_
 
 #include "base/memory/raw_ptr.h"
+#include "content/common/content_export.h"
 
 namespace content {
 
@@ -26,7 +27,7 @@ struct NativeWebKeyboardEvent;
 
 // TODO(wjmaclean): Get rid of "BrowserPlugin" in the name of this class.
 // Perhaps "WebContentsEmbedderDelegate" would be better?
-class BrowserPluginEmbedder {
+class CONTENT_EXPORT BrowserPluginEmbedder {
  public:
   BrowserPluginEmbedder(const BrowserPluginEmbedder&) = delete;
   BrowserPluginEmbedder& operator=(const BrowserPluginEmbedder&) = delete;
diff --git content/browser/browser_plugin/browser_plugin_guest.cc content/browser/browser_plugin/browser_plugin_guest.cc
index a731c5ef5b714..99e313b92c242 100644
--- content/browser/browser_plugin/browser_plugin_guest.cc
+++ content/browser/browser_plugin/browser_plugin_guest.cc
@@ -80,6 +80,8 @@ void BrowserPluginGuest::InitInternal(WebContentsImpl* owner_web_contents) {
       GetWebContents()->GetOrCreateWebPreferences();
   prefs.navigate_on_drag_drop = false;
   GetWebContents()->SetWebPreferences(prefs);
+
+  owner_web_contents_ = owner_web_contents;
 }
 
 BrowserPluginGuest::~BrowserPluginGuest() = default;
diff --git content/browser/browser_plugin/browser_plugin_guest.h content/browser/browser_plugin/browser_plugin_guest.h
index aec6a0eb9cbd0..286e7de6887a7 100644
--- content/browser/browser_plugin/browser_plugin_guest.h
+++ content/browser/browser_plugin/browser_plugin_guest.h
@@ -68,6 +68,8 @@ class BrowserPluginGuest : public WebContentsObserver {
 
   WebContentsImpl* GetWebContents() const;
 
+  WebContentsImpl* owner_web_contents() const { return owner_web_contents_; }
+
  private:
   // BrowserPluginGuest is a WebContentsObserver of |web_contents| and
   // |web_contents| has to stay valid for the lifetime of BrowserPluginGuest.
@@ -77,6 +79,8 @@ class BrowserPluginGuest : public WebContentsObserver {
   void InitInternal(WebContentsImpl* owner_web_contents);
 
   const raw_ptr<BrowserPluginGuestDelegate, DanglingUntriaged> delegate_;
+
+  raw_ptr<WebContentsImpl> owner_web_contents_ = nullptr;
 };
 
 }  // namespace content