diff --git a/BUILD.gn b/BUILD.gn
index 2d7bea5ef..d4ee0be46 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -411,6 +411,8 @@ static_library("libcef_static") {
     "libcef/browser/alloy/alloy_browser_context.h",
     "libcef/browser/alloy/alloy_browser_main.cc",
     "libcef/browser/alloy/alloy_browser_main.h",
+    "libcef/browser/alloy/browser_platform_delegate_alloy.cc",
+    "libcef/browser/alloy/browser_platform_delegate_alloy.h",
     "libcef/browser/alloy/chrome_browser_process_alloy.cc",
     "libcef/browser/alloy/chrome_browser_process_alloy.h",
     "libcef/browser/alloy/chrome_profile_manager_alloy.cc",
diff --git a/libcef/browser/alloy/browser_platform_delegate_alloy.cc b/libcef/browser/alloy/browser_platform_delegate_alloy.cc
new file mode 100644
index 000000000..c6b898583
--- /dev/null
+++ b/libcef/browser/alloy/browser_platform_delegate_alloy.cc
@@ -0,0 +1,427 @@
+// Copyright 2015 The Chromium Embedded Framework Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "libcef/browser/alloy/browser_platform_delegate_alloy.h"
+
+#include "libcef/browser/browser_host_impl.h"
+#include "libcef/browser/extensions/browser_extensions_util.h"
+#include "libcef/browser/extensions/extension_background_host.h"
+#include "libcef/browser/extensions/extension_system.h"
+#include "libcef/browser/extensions/extension_view_host.h"
+#include "libcef/browser/extensions/extension_web_contents_observer.h"
+#include "libcef/browser/printing/print_view_manager.h"
+#include "libcef/common/extensions/extensions_util.h"
+
+#include "base/logging.h"
+#include "chrome/browser/printing/print_view_manager.h"
+#include "chrome/browser/ui/prefs/prefs_tab_helper.h"
+#include "components/zoom/zoom_controller.h"
+#include "content/browser/renderer_host/render_widget_host_impl.h"
+#include "content/browser/web_contents/web_contents_impl.h"
+#include "content/public/browser/render_view_host.h"
+#include "content/public/browser/render_widget_host.h"
+#include "extensions/browser/process_manager.h"
+#include "third_party/blink/public/mojom/frame/find_in_page.mojom.h"
+
+CefBrowserPlatformDelegateAlloy::CefBrowserPlatformDelegateAlloy()
+    : weak_ptr_factory_(this) {}
+
+content::WebContents* CefBrowserPlatformDelegateAlloy::CreateWebContents(
+    CefBrowserHostImpl::CreateParams& create_params,
+    bool& own_web_contents) {
+  // Get or create the request context and browser context.
+  CefRefPtr<CefRequestContextImpl> request_context_impl =
+      CefRequestContextImpl::GetOrCreateForRequestContext(
+          create_params.request_context);
+  CHECK(request_context_impl);
+  auto cef_browser_context = request_context_impl->GetBrowserContext();
+  CHECK(cef_browser_context);
+  auto browser_context = cef_browser_context->AsBrowserContext();
+
+  if (!create_params.request_context) {
+    // Using the global request context.
+    create_params.request_context = request_context_impl.get();
+  }
+
+  scoped_refptr<content::SiteInstance> site_instance;
+  if (extensions::ExtensionsEnabled() && !create_params.url.is_empty()) {
+    if (!create_params.extension) {
+      // We might be loading an extension app view where the extension URL is
+      // provided by the client.
+      create_params.extension =
+          extensions::GetExtensionForUrl(browser_context, create_params.url);
+    }
+    if (create_params.extension) {
+      if (create_params.extension_host_type == extensions::VIEW_TYPE_INVALID) {
+        // Default to dialog behavior.
+        create_params.extension_host_type =
+            extensions::VIEW_TYPE_EXTENSION_DIALOG;
+      }
+
+      // Extension resources will fail to load if we don't use a SiteInstance
+      // associated with the extension.
+      // (AlloyContentBrowserClient::SiteInstanceGotProcess won't find the
+      // extension to register with InfoMap, and AllowExtensionResourceLoad in
+      // ExtensionProtocolHandler::MaybeCreateJob will return false resulting in
+      // ERR_BLOCKED_BY_CLIENT).
+      site_instance = extensions::ProcessManager::Get(browser_context)
+                          ->GetSiteInstanceForURL(create_params.url);
+      DCHECK(site_instance);
+    }
+  }
+
+  content::WebContents::CreateParams wc_create_params(browser_context,
+                                                      site_instance);
+
+  if (IsWindowless()) {
+    // Create the OSR view for the WebContents.
+    CreateViewForWebContents(&wc_create_params.view,
+                             &wc_create_params.delegate_view);
+  }
+
+  auto web_contents = content::WebContents::Create(wc_create_params);
+  CHECK(web_contents);
+
+  own_web_contents = true;
+  return web_contents.release();
+}
+
+void CefBrowserPlatformDelegateAlloy::WebContentsCreated(
+    content::WebContents* web_contents,
+    bool owned) {
+  CefBrowserPlatformDelegate::WebContentsCreated(web_contents, owned);
+
+  if (owned) {
+    SetOwnedWebContents(web_contents);
+  }
+}
+
+void CefBrowserPlatformDelegateAlloy::AddNewContents(
+    content::WebContents* source,
+    std::unique_ptr<content::WebContents> new_contents,
+    const GURL& target_url,
+    WindowOpenDisposition disposition,
+    const gfx::Rect& initial_rect,
+    bool user_gesture,
+    bool* was_blocked) {
+  CefRefPtr<CefBrowserHostImpl> owner =
+      CefBrowserHostImpl::GetBrowserForContents(new_contents.get());
+  if (owner) {
+    // Taking ownership of |new_contents|.
+    static_cast<CefBrowserPlatformDelegateAlloy*>(
+        owner->platform_delegate_.get())
+        ->SetOwnedWebContents(new_contents.release());
+    return;
+  }
+
+  if (extension_host_) {
+    extension_host_->AddNewContents(source, std::move(new_contents), target_url,
+                                    disposition, initial_rect, user_gesture,
+                                    was_blocked);
+  }
+}
+
+bool CefBrowserPlatformDelegateAlloy::ShouldTransferNavigation(
+    bool is_main_frame_navigation) {
+  if (extension_host_) {
+    return extension_host_->ShouldTransferNavigation(is_main_frame_navigation);
+  }
+  return true;
+}
+
+void CefBrowserPlatformDelegateAlloy::RenderViewCreated(
+    content::RenderViewHost* render_view_host) {
+  // Indicate that the view has an external parent (namely us). This changes the
+  // default view behavior in some cases (e.g. focus handling on Linux).
+  if (!IsViewsHosted() && render_view_host->GetWidget()->GetView())
+    render_view_host->GetWidget()->GetView()->SetHasExternalParent(true);
+}
+
+void CefBrowserPlatformDelegateAlloy::RenderViewReady() {
+  ConfigureAutoResize();
+}
+
+void CefBrowserPlatformDelegateAlloy::BrowserCreated(
+    CefBrowserHostImpl* browser) {
+  CefBrowserPlatformDelegate::BrowserCreated(browser);
+
+  web_contents_->SetDelegate(browser);
+
+  PrefsTabHelper::CreateForWebContents(web_contents_);
+  printing::CefPrintViewManager::CreateForWebContents(web_contents_);
+
+  if (extensions::ExtensionsEnabled()) {
+    extensions::CefExtensionWebContentsObserver::CreateForWebContents(
+        web_contents_);
+
+    // Used by the tabs extension API.
+    zoom::ZoomController::CreateForWebContents(web_contents_);
+  }
+
+  if (IsPrintPreviewSupported()) {
+    web_contents_dialog_helper_.reset(
+        new CefWebContentsDialogHelper(web_contents_, this));
+  }
+}
+
+void CefBrowserPlatformDelegateAlloy::CreateExtensionHost(
+    const extensions::Extension* extension,
+    const GURL& url,
+    extensions::ViewType host_type) {
+  // Should get WebContentsCreated and BrowserCreated calls first.
+  DCHECK(web_contents_);
+  DCHECK(browser_);
+  DCHECK(!extension_host_);
+
+  if (host_type == extensions::VIEW_TYPE_EXTENSION_DIALOG ||
+      host_type == extensions::VIEW_TYPE_EXTENSION_POPUP) {
+    // Create an extension host that we own.
+    extension_host_ = new extensions::CefExtensionViewHost(
+        browser_, extension, web_contents_, url, host_type);
+    // Trigger load of the extension URL.
+    extension_host_->CreateRenderViewSoon();
+  } else if (host_type == extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
+    is_background_host_ = true;
+    browser_->is_background_host_ = true;
+    // Create an extension host that will be owned by ProcessManager.
+    extension_host_ = new extensions::CefExtensionBackgroundHost(
+        browser_,
+        base::BindOnce(&CefBrowserPlatformDelegateAlloy::OnExtensionHostDeleted,
+                       weak_ptr_factory_.GetWeakPtr()),
+        extension, web_contents_, url, host_type);
+    // Load will be triggered by ProcessManager::CreateBackgroundHost.
+  } else {
+    NOTREACHED() << " Unsupported extension host type: " << host_type;
+  }
+}
+
+extensions::ExtensionHost* CefBrowserPlatformDelegateAlloy::GetExtensionHost()
+    const {
+  return extension_host_;
+}
+
+void CefBrowserPlatformDelegateAlloy::BrowserDestroyed(
+    CefBrowserHostImpl* browser) {
+  DestroyExtensionHost();
+  owned_web_contents_.reset();
+
+  CefBrowserPlatformDelegate::BrowserDestroyed(browser);
+}
+
+void CefBrowserPlatformDelegateAlloy::SendCaptureLostEvent() {
+  content::RenderWidgetHostImpl* widget = content::RenderWidgetHostImpl::From(
+      browser_->web_contents()->GetRenderViewHost()->GetWidget());
+  if (widget)
+    widget->LostCapture();
+}
+
+#if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MACOSX))
+void CefBrowserPlatformDelegateAlloy::NotifyMoveOrResizeStarted() {
+  // Dismiss any existing popups.
+  content::RenderViewHost* host = browser_->web_contents()->GetRenderViewHost();
+  if (host)
+    host->NotifyMoveOrResizeStarted();
+}
+#endif
+
+bool CefBrowserPlatformDelegateAlloy::PreHandleGestureEvent(
+    content::WebContents* source,
+    const blink::WebGestureEvent& event) {
+  if (extension_host_)
+    return extension_host_->PreHandleGestureEvent(source, event);
+  return false;
+}
+
+bool CefBrowserPlatformDelegateAlloy::IsNeverComposited(
+    content::WebContents* web_contents) {
+  if (extension_host_)
+    return extension_host_->IsNeverComposited(web_contents);
+  return false;
+}
+
+void CefBrowserPlatformDelegateAlloy::SetAutoResizeEnabled(
+    bool enabled,
+    const CefSize& min_size,
+    const CefSize& max_size) {
+  if (enabled == auto_resize_enabled_)
+    return;
+
+  auto_resize_enabled_ = enabled;
+  if (enabled) {
+    auto_resize_min_ = gfx::Size(min_size.width, min_size.height);
+    auto_resize_max_ = gfx::Size(max_size.width, max_size.height);
+  } else {
+    auto_resize_min_ = auto_resize_max_ = gfx::Size();
+  }
+  ConfigureAutoResize();
+}
+
+void CefBrowserPlatformDelegateAlloy::ConfigureAutoResize() {
+  if (!web_contents_ || !web_contents_->GetRenderWidgetHostView()) {
+    return;
+  }
+
+  if (auto_resize_enabled_) {
+    web_contents_->GetRenderWidgetHostView()->EnableAutoResize(
+        auto_resize_min_, auto_resize_max_);
+  } else {
+    web_contents_->GetRenderWidgetHostView()->DisableAutoResize(gfx::Size());
+  }
+}
+
+void CefBrowserPlatformDelegateAlloy::SetAccessibilityState(
+    cef_state_t accessibility_state) {
+  // Do nothing if state is set to default. It'll be disabled by default and
+  // controlled by the commmand-line flags "force-renderer-accessibility" and
+  // "disable-renderer-accessibility".
+  if (accessibility_state == STATE_DEFAULT)
+    return;
+
+  content::WebContentsImpl* web_contents_impl =
+      static_cast<content::WebContentsImpl*>(web_contents_);
+
+  if (!web_contents_impl)
+    return;
+
+  ui::AXMode accMode;
+  // In windowless mode set accessibility to TreeOnly mode. Else native
+  // accessibility APIs, specific to each platform, are also created.
+  if (accessibility_state == STATE_ENABLED) {
+    accMode = IsWindowless() ? ui::kAXModeWebContentsOnly : ui::kAXModeComplete;
+  }
+  web_contents_impl->SetAccessibilityMode(accMode);
+}
+
+bool CefBrowserPlatformDelegateAlloy::IsPrintPreviewSupported() const {
+  auto actionable_contents = GetActionableWebContents();
+  if (!actionable_contents)
+    return false;
+
+  auto cef_browser_context = CefBrowserContext::FromBrowserContext(
+      actionable_contents->GetBrowserContext());
+  if (!cef_browser_context->IsPrintPreviewSupported()) {
+    return false;
+  }
+
+  // Print preview is not currently supported with OSR.
+  return !IsWindowless();
+}
+
+void CefBrowserPlatformDelegateAlloy::Print() {
+  auto actionable_contents = GetActionableWebContents();
+  if (!actionable_contents)
+    return;
+
+  auto rfh = actionable_contents->GetMainFrame();
+
+  if (IsPrintPreviewSupported()) {
+    printing::CefPrintViewManager::FromWebContents(actionable_contents)
+        ->PrintPreviewNow(rfh, false);
+  } else {
+    printing::PrintViewManager::FromWebContents(actionable_contents)
+        ->PrintNow(rfh);
+  }
+}
+
+void CefBrowserPlatformDelegateAlloy::PrintToPDF(
+    const CefString& path,
+    const CefPdfPrintSettings& settings,
+    CefRefPtr<CefPdfPrintCallback> callback) {
+  content::WebContents* actionable_contents = GetActionableWebContents();
+  if (!actionable_contents)
+    return;
+  printing::CefPrintViewManager::PdfPrintCallback pdf_callback;
+  if (callback.get()) {
+    pdf_callback = base::Bind(&CefPdfPrintCallback::OnPdfPrintFinished,
+                              callback.get(), path);
+  }
+  printing::CefPrintViewManager::FromWebContents(actionable_contents)
+      ->PrintToPDF(actionable_contents->GetMainFrame(), base::FilePath(path),
+                   settings, pdf_callback);
+}
+
+void CefBrowserPlatformDelegateAlloy::Find(int identifier,
+                                           const CefString& searchText,
+                                           bool forward,
+                                           bool matchCase,
+                                           bool findNext) {
+  if (!web_contents_)
+    return;
+
+  // Every find request must have a unique ID and these IDs must strictly
+  // increase so that newer requests always have greater IDs than older
+  // requests.
+  if (identifier <= find_request_id_counter_)
+    identifier = ++find_request_id_counter_;
+  else
+    find_request_id_counter_ = identifier;
+
+  auto options = blink::mojom::FindOptions::New();
+  options->forward = forward;
+  options->match_case = matchCase;
+  options->find_next = findNext;
+  web_contents_->Find(identifier, searchText, std::move(options));
+}
+
+void CefBrowserPlatformDelegateAlloy::StopFinding(bool clearSelection) {
+  if (!web_contents_)
+    return;
+
+  content::StopFindAction action =
+      clearSelection ? content::STOP_FIND_ACTION_CLEAR_SELECTION
+                     : content::STOP_FIND_ACTION_KEEP_SELECTION;
+  web_contents_->StopFinding(action);
+}
+
+base::RepeatingClosure
+CefBrowserPlatformDelegateAlloy::GetBoundsChangedCallback() {
+  if (web_contents_dialog_helper_) {
+    return web_contents_dialog_helper_->GetBoundsChangedCallback();
+  }
+
+  return base::RepeatingClosure();
+}
+
+content::WebContents*
+CefBrowserPlatformDelegateAlloy::GetActionableWebContents() const {
+  if (web_contents_ && extensions::ExtensionsEnabled()) {
+    content::WebContents* guest_contents =
+        extensions::GetFullPageGuestForOwnerContents(web_contents_);
+    if (guest_contents)
+      return guest_contents;
+  }
+  return web_contents_;
+}
+
+void CefBrowserPlatformDelegateAlloy::SetOwnedWebContents(
+    content::WebContents* owned_contents) {
+  // Should not currently own a WebContents.
+  CHECK(!owned_web_contents_);
+  owned_web_contents_.reset(owned_contents);
+}
+
+void CefBrowserPlatformDelegateAlloy::DestroyExtensionHost() {
+  if (!extension_host_)
+    return;
+  if (extension_host_->extension_host_type() ==
+      extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
+    DCHECK(is_background_host_);
+    // Close notification for background pages arrives via CloseContents.
+    // The extension host will be deleted by
+    // ProcessManager::CloseBackgroundHost and OnExtensionHostDeleted will be
+    // called to notify us.
+    extension_host_->Close();
+  } else {
+    DCHECK(!is_background_host_);
+    // We own the extension host and must delete it.
+    delete extension_host_;
+    extension_host_ = nullptr;
+  }
+}
+
+void CefBrowserPlatformDelegateAlloy::OnExtensionHostDeleted() {
+  DCHECK(is_background_host_);
+  DCHECK(extension_host_);
+  extension_host_ = nullptr;
+}
diff --git a/libcef/browser/alloy/browser_platform_delegate_alloy.h b/libcef/browser/alloy/browser_platform_delegate_alloy.h
new file mode 100644
index 000000000..7a989538a
--- /dev/null
+++ b/libcef/browser/alloy/browser_platform_delegate_alloy.h
@@ -0,0 +1,106 @@
+// Copyright (c) 2015 The Chromium Embedded Framework Authors.
+// Portions copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CEF_LIBCEF_BROWSER_ALLOY_BROWSER_PLATFORM_DELEGATE_ALLOY_H_
+#define CEF_LIBCEF_BROWSER_ALLOY_BROWSER_PLATFORM_DELEGATE_ALLOY_H_
+
+#include "libcef/browser/browser_platform_delegate.h"
+#include "libcef/browser/web_contents_dialog_helper.h"
+
+#include "base/memory/weak_ptr.h"
+
+// Implementation of Alloy-based browser functionality.
+class CefBrowserPlatformDelegateAlloy : public CefBrowserPlatformDelegate {
+ public:
+  content::WebContents* CreateWebContents(
+      CefBrowserHostImpl::CreateParams& create_params,
+      bool& own_web_contents) override;
+  void WebContentsCreated(content::WebContents* web_contents,
+                          bool owned) override;
+  void AddNewContents(content::WebContents* source,
+                      std::unique_ptr<content::WebContents> new_contents,
+                      const GURL& target_url,
+                      WindowOpenDisposition disposition,
+                      const gfx::Rect& initial_rect,
+                      bool user_gesture,
+                      bool* was_blocked) override;
+  bool ShouldTransferNavigation(bool is_main_frame_navigation) override;
+  void RenderViewCreated(content::RenderViewHost* render_view_host) override;
+  void RenderViewReady() override;
+  void BrowserCreated(CefBrowserHostImpl* browser) override;
+  void CreateExtensionHost(const extensions::Extension* extension,
+                           const GURL& url,
+                           extensions::ViewType host_type) override;
+  extensions::ExtensionHost* GetExtensionHost() const override;
+  void BrowserDestroyed(CefBrowserHostImpl* browser) override;
+  void SendCaptureLostEvent() override;
+#if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MACOSX))
+  void NotifyMoveOrResizeStarted() override;
+#endif
+  bool PreHandleGestureEvent(content::WebContents* source,
+                             const blink::WebGestureEvent& event) override;
+  bool IsNeverComposited(content::WebContents* web_contents) override;
+  void SetAutoResizeEnabled(bool enabled,
+                            const CefSize& min_size,
+                            const CefSize& max_size) override;
+  void SetAccessibilityState(cef_state_t accessibility_state) override;
+  bool IsPrintPreviewSupported() const override;
+  void Print() override;
+  void PrintToPDF(const CefString& path,
+                  const CefPdfPrintSettings& settings,
+                  CefRefPtr<CefPdfPrintCallback> callback) override;
+  void Find(int identifier,
+            const CefString& searchText,
+            bool forward,
+            bool matchCase,
+            bool findNext) override;
+  void StopFinding(bool clearSelection) override;
+
+ protected:
+  CefBrowserPlatformDelegateAlloy();
+
+  base::RepeatingClosure GetBoundsChangedCallback();
+
+  // Returns the WebContents most likely to handle an action. If extensions are
+  // enabled and this browser has a full-page guest (for example, a full-page
+  // PDF viewer extension) then the guest's WebContents will be returned.
+  // Otherwise, the browser's WebContents will be returned.
+  content::WebContents* GetActionableWebContents() const;
+
+ private:
+  void SetOwnedWebContents(content::WebContents* owned_contents);
+
+  void DestroyExtensionHost();
+  void OnExtensionHostDeleted();
+
+  void ConfigureAutoResize();
+
+  // Non-nullptr if this object owns the WebContents. Will be nullptr for popup
+  // browsers between the calls to WebContentsCreated() and AddNewContents(),
+  // and may never be set if the parent browser is destroyed during popup
+  // creation.
+  std::unique_ptr<content::WebContents> owned_web_contents_;
+
+  // Used for the print preview dialog.
+  std::unique_ptr<CefWebContentsDialogHelper> web_contents_dialog_helper_;
+
+  // Used to provide unique incremental IDs for each find request.
+  int find_request_id_counter_ = 0;
+
+  // Used when the browser is hosting an extension.
+  extensions::ExtensionHost* extension_host_ = nullptr;
+  bool is_background_host_ = false;
+
+  // Used with auto-resize.
+  bool auto_resize_enabled_ = false;
+  gfx::Size auto_resize_min_;
+  gfx::Size auto_resize_max_;
+
+  base::WeakPtrFactory<CefBrowserPlatformDelegateAlloy> weak_ptr_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(CefBrowserPlatformDelegateAlloy);
+};
+
+#endif  // CEF_LIBCEF_BROWSER_ALLOY_BROWSER_PLATFORM_DELEGATE_ALLOY_H_
diff --git a/libcef/browser/browser_host_impl.cc b/libcef/browser/browser_host_impl.cc
index db251db85..b6e41f35b 100644
--- a/libcef/browser/browser_host_impl.cc
+++ b/libcef/browser/browser_host_impl.cc
@@ -1658,7 +1658,7 @@ content::BrowserContext* CefBrowserHostImpl::GetBrowserContext() const {
 extensions::ExtensionHost* CefBrowserHostImpl::GetExtensionHost() const {
   CEF_REQUIRE_UIT();
   DCHECK(platform_delegate_);
-  return platform_delegate_->extension_host();
+  return platform_delegate_->GetExtensionHost();
 }
 
 void CefBrowserHostImpl::OnSetFocus(cef_focus_source_t source) {
@@ -2490,7 +2490,7 @@ void CefBrowserHostImpl::RenderViewDeleted(
 }
 
 void CefBrowserHostImpl::RenderViewReady() {
-  platform_delegate_->ConfigureAutoResize();
+  platform_delegate_->RenderViewReady();
 
   if (client_.get()) {
     CefRefPtr<CefRequestHandler> handler = client_->GetRequestHandler();
diff --git a/libcef/browser/browser_host_impl.h b/libcef/browser/browser_host_impl.h
index 7f50dc481..5fee920bb 100644
--- a/libcef/browser/browser_host_impl.h
+++ b/libcef/browser/browser_host_impl.h
@@ -523,7 +523,7 @@ class CefBrowserHostImpl : public CefBrowserHost,
   std::unique_ptr<NavigationLock> CreateNavigationLock();
 
  private:
-  friend class CefBrowserPlatformDelegate;
+  friend class CefBrowserPlatformDelegateAlloy;
 
   static CefRefPtr<CefBrowserHostImpl> CreateInternal(
       const CefBrowserSettings& settings,
diff --git a/libcef/browser/browser_platform_delegate.cc b/libcef/browser/browser_platform_delegate.cc
index 882f8040e..1e209d0b3 100644
--- a/libcef/browser/browser_platform_delegate.cc
+++ b/libcef/browser/browser_platform_delegate.cc
@@ -5,97 +5,15 @@
 #include "libcef/browser/browser_platform_delegate.h"
 
 #include "libcef/browser/browser_host_impl.h"
-#include "libcef/browser/extensions/browser_extensions_util.h"
-#include "libcef/browser/extensions/extension_background_host.h"
-#include "libcef/browser/extensions/extension_system.h"
-#include "libcef/browser/extensions/extension_view_host.h"
-#include "libcef/browser/extensions/extension_web_contents_observer.h"
-#include "libcef/browser/printing/print_view_manager.h"
-#include "libcef/browser/web_contents_dialog_helper.h"
-#include "libcef/common/extensions/extensions_util.h"
-#include "libcef/features/runtime_checks.h"
 
 #include "base/logging.h"
-#include "chrome/browser/printing/print_view_manager.h"
-#include "chrome/browser/ui/prefs/prefs_tab_helper.h"
-#include "components/zoom/zoom_controller.h"
-#include "content/browser/renderer_host/render_widget_host_impl.h"
-#include "content/browser/web_contents/web_contents_impl.h"
-#include "content/public/browser/render_view_host.h"
-#include "content/public/browser/render_widget_host.h"
-#include "extensions/browser/process_manager.h"
-#include "third_party/blink/public/mojom/frame/find_in_page.mojom.h"
 
-CefBrowserPlatformDelegate::CefBrowserPlatformDelegate()
-    : weak_ptr_factory_(this) {}
+CefBrowserPlatformDelegate::CefBrowserPlatformDelegate() = default;
 
 CefBrowserPlatformDelegate::~CefBrowserPlatformDelegate() {
   DCHECK(!browser_);
 }
 
-content::WebContents* CefBrowserPlatformDelegate::CreateWebContents(
-    CefBrowserHostImpl::CreateParams& create_params,
-    bool& own_web_contents) {
-  // TODO(chrome-runtime): Add a path to create a Browser.
-  REQUIRE_ALLOY_RUNTIME();
-
-  // Get or create the request context and browser context.
-  CefRefPtr<CefRequestContextImpl> request_context_impl =
-      CefRequestContextImpl::GetOrCreateForRequestContext(
-          create_params.request_context);
-  CHECK(request_context_impl);
-  auto cef_browser_context = request_context_impl->GetBrowserContext();
-  CHECK(cef_browser_context);
-  auto browser_context = cef_browser_context->AsBrowserContext();
-
-  if (!create_params.request_context) {
-    // Using the global request context.
-    create_params.request_context = request_context_impl.get();
-  }
-
-  scoped_refptr<content::SiteInstance> site_instance;
-  if (extensions::ExtensionsEnabled() && !create_params.url.is_empty()) {
-    if (!create_params.extension) {
-      // We might be loading an extension app view where the extension URL is
-      // provided by the client.
-      create_params.extension =
-          extensions::GetExtensionForUrl(browser_context, create_params.url);
-    }
-    if (create_params.extension) {
-      if (create_params.extension_host_type == extensions::VIEW_TYPE_INVALID) {
-        // Default to dialog behavior.
-        create_params.extension_host_type =
-            extensions::VIEW_TYPE_EXTENSION_DIALOG;
-      }
-
-      // Extension resources will fail to load if we don't use a SiteInstance
-      // associated with the extension.
-      // (AlloyContentBrowserClient::SiteInstanceGotProcess won't find the
-      // extension to register with InfoMap, and AllowExtensionResourceLoad in
-      // ExtensionProtocolHandler::MaybeCreateJob will return false resulting in
-      // ERR_BLOCKED_BY_CLIENT).
-      site_instance = extensions::ProcessManager::Get(browser_context)
-                          ->GetSiteInstanceForURL(create_params.url);
-      DCHECK(site_instance);
-    }
-  }
-
-  content::WebContents::CreateParams wc_create_params(browser_context,
-                                                      site_instance);
-
-  if (IsWindowless()) {
-    // Create the OSR view for the WebContents.
-    CreateViewForWebContents(&wc_create_params.view,
-                             &wc_create_params.delegate_view);
-  }
-
-  auto web_contents = content::WebContents::Create(wc_create_params);
-  CHECK(web_contents);
-
-  own_web_contents = true;
-  return web_contents.release();
-}
-
 void CefBrowserPlatformDelegate::CreateViewForWebContents(
     content::WebContentsView** view,
     content::RenderViewHostDelegateView** delegate_view) {
@@ -110,9 +28,6 @@ void CefBrowserPlatformDelegate::WebContentsCreated(
 
   DCHECK(!web_contents_);
   web_contents_ = web_contents;
-  if (owned) {
-    SetOwnedWebContents(web_contents);
-  }
 }
 
 void CefBrowserPlatformDelegate::AddNewContents(
@@ -123,21 +38,7 @@ void CefBrowserPlatformDelegate::AddNewContents(
     const gfx::Rect& initial_rect,
     bool user_gesture,
     bool* was_blocked) {
-  REQUIRE_ALLOY_RUNTIME();
-
-  CefRefPtr<CefBrowserHostImpl> owner =
-      CefBrowserHostImpl::GetBrowserForContents(new_contents.get());
-  if (owner) {
-    // Taking ownership of |new_contents|.
-    owner->platform_delegate_->SetOwnedWebContents(new_contents.release());
-    return;
-  }
-
-  if (extension_host_) {
-    extension_host_->AddNewContents(source, std::move(new_contents), target_url,
-                                    disposition, initial_rect, user_gesture,
-                                    was_blocked);
-  }
+  NOTREACHED();
 }
 
 void CefBrowserPlatformDelegate::WebContentsDestroyed(
@@ -148,19 +49,13 @@ void CefBrowserPlatformDelegate::WebContentsDestroyed(
 
 bool CefBrowserPlatformDelegate::ShouldTransferNavigation(
     bool is_main_frame_navigation) {
-  if (extension_host_) {
-    return extension_host_->ShouldTransferNavigation(is_main_frame_navigation);
-  }
   return true;
 }
 
 void CefBrowserPlatformDelegate::RenderViewCreated(
-    content::RenderViewHost* render_view_host) {
-  // Indicate that the view has an external parent (namely us). This changes the
-  // default view behavior in some cases (e.g. focus handling on Linux).
-  if (!IsViewsHosted() && render_view_host->GetWidget()->GetView())
-    render_view_host->GetWidget()->GetView()->SetHasExternalParent(true);
-}
+    content::RenderViewHost* render_view_host) {}
+
+void CefBrowserPlatformDelegate::RenderViewReady() {}
 
 void CefBrowserPlatformDelegate::BrowserCreated(CefBrowserHostImpl* browser) {
   // We should have an associated WebContents at this point.
@@ -169,55 +64,19 @@ void CefBrowserPlatformDelegate::BrowserCreated(CefBrowserHostImpl* browser) {
   DCHECK(!browser_);
   DCHECK(browser);
   browser_ = browser;
-
-  web_contents_->SetDelegate(browser);
-
-  PrefsTabHelper::CreateForWebContents(web_contents_);
-  printing::CefPrintViewManager::CreateForWebContents(web_contents_);
-
-  if (extensions::ExtensionsEnabled()) {
-    extensions::CefExtensionWebContentsObserver::CreateForWebContents(
-        web_contents_);
-
-    // Used by the tabs extension API.
-    zoom::ZoomController::CreateForWebContents(web_contents_);
-  }
-
-  if (IsPrintPreviewSupported()) {
-    web_contents_dialog_helper_.reset(
-        new CefWebContentsDialogHelper(web_contents_, this));
-  }
 }
 
 void CefBrowserPlatformDelegate::CreateExtensionHost(
     const extensions::Extension* extension,
     const GURL& url,
     extensions::ViewType host_type) {
-  // Should get WebContentsCreated and BrowserCreated calls first.
-  DCHECK(web_contents_);
-  DCHECK(browser_);
-  DCHECK(!extension_host_);
+  NOTREACHED();
+}
 
-  if (host_type == extensions::VIEW_TYPE_EXTENSION_DIALOG ||
-      host_type == extensions::VIEW_TYPE_EXTENSION_POPUP) {
-    // Create an extension host that we own.
-    extension_host_ = new extensions::CefExtensionViewHost(
-        browser_, extension, web_contents_, url, host_type);
-    // Trigger load of the extension URL.
-    extension_host_->CreateRenderViewSoon();
-  } else if (host_type == extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
-    is_background_host_ = true;
-    browser_->is_background_host_ = true;
-    // Create an extension host that will be owned by ProcessManager.
-    extension_host_ = new extensions::CefExtensionBackgroundHost(
-        browser_,
-        base::BindOnce(&CefBrowserPlatformDelegate::OnExtensionHostDeleted,
-                       weak_ptr_factory_.GetWeakPtr()),
-        extension, web_contents_, url, host_type);
-    // Load will be triggered by ProcessManager::CreateBackgroundHost.
-  } else {
-    NOTREACHED() << " Unsupported extension host type: " << host_type;
-  }
+extensions::ExtensionHost* CefBrowserPlatformDelegate::GetExtensionHost()
+    const {
+  NOTREACHED();
+  return nullptr;
 }
 
 void CefBrowserPlatformDelegate::NotifyBrowserCreated() {}
@@ -228,9 +87,6 @@ void CefBrowserPlatformDelegate::BrowserDestroyed(CefBrowserHostImpl* browser) {
   // WebContentsDestroyed should already be called.
   DCHECK(!web_contents_);
 
-  DestroyExtensionHost();
-  owned_web_contents_.reset();
-
   DCHECK(browser_ && browser_ == browser);
   browser_ = nullptr;
 }
@@ -268,19 +124,11 @@ void CefBrowserPlatformDelegate::PopupBrowserCreated(
     bool is_devtools) {}
 
 void CefBrowserPlatformDelegate::SendCaptureLostEvent() {
-  content::RenderWidgetHostImpl* widget = content::RenderWidgetHostImpl::From(
-      browser_->web_contents()->GetRenderViewHost()->GetWidget());
-  if (widget)
-    widget->LostCapture();
+  NOTIMPLEMENTED();
 }
 
 #if defined(OS_WIN) || (defined(OS_POSIX) && !defined(OS_MACOSX))
-void CefBrowserPlatformDelegate::NotifyMoveOrResizeStarted() {
-  // Dismiss any existing popups.
-  content::RenderViewHost* host = browser_->web_contents()->GetRenderViewHost();
-  if (host)
-    host->NotifyMoveOrResizeStarted();
-}
+void CefBrowserPlatformDelegate::NotifyMoveOrResizeStarted() {}
 
 void CefBrowserPlatformDelegate::SizeTo(int width, int height) {}
 #endif
@@ -288,25 +136,23 @@ void CefBrowserPlatformDelegate::SizeTo(int width, int height) {}
 bool CefBrowserPlatformDelegate::PreHandleGestureEvent(
     content::WebContents* source,
     const blink::WebGestureEvent& event) {
-  if (extension_host_)
-    return extension_host_->PreHandleGestureEvent(source, event);
   return false;
 }
 
 bool CefBrowserPlatformDelegate::IsNeverComposited(
     content::WebContents* web_contents) {
-  if (extension_host_)
-    return extension_host_->IsNeverComposited(web_contents);
   return false;
 }
 
 std::unique_ptr<CefFileDialogRunner>
 CefBrowserPlatformDelegate::CreateFileDialogRunner() {
+  NOTIMPLEMENTED();
   return nullptr;
 }
 
 std::unique_ptr<CefJavaScriptDialogRunner>
 CefBrowserPlatformDelegate::CreateJavaScriptDialogRunner() {
+  NOTIMPLEMENTED();
   return nullptr;
 }
 
@@ -424,102 +270,27 @@ gfx::Size CefBrowserPlatformDelegate::GetMaximumDialogSize() {
 void CefBrowserPlatformDelegate::SetAutoResizeEnabled(bool enabled,
                                                       const CefSize& min_size,
                                                       const CefSize& max_size) {
-  if (enabled == auto_resize_enabled_)
-    return;
-
-  auto_resize_enabled_ = enabled;
-  if (enabled) {
-    auto_resize_min_ = gfx::Size(min_size.width, min_size.height);
-    auto_resize_max_ = gfx::Size(max_size.width, max_size.height);
-  } else {
-    auto_resize_min_ = auto_resize_max_ = gfx::Size();
-  }
-  ConfigureAutoResize();
-}
-
-void CefBrowserPlatformDelegate::ConfigureAutoResize() {
-  if (!web_contents_ || !web_contents_->GetRenderWidgetHostView()) {
-    return;
-  }
-
-  if (auto_resize_enabled_) {
-    web_contents_->GetRenderWidgetHostView()->EnableAutoResize(
-        auto_resize_min_, auto_resize_max_);
-  } else {
-    web_contents_->GetRenderWidgetHostView()->DisableAutoResize(gfx::Size());
-  }
+  NOTIMPLEMENTED();
 }
 
 void CefBrowserPlatformDelegate::SetAccessibilityState(
     cef_state_t accessibility_state) {
-  // Do nothing if state is set to default. It'll be disabled by default and
-  // controlled by the commmand-line flags "force-renderer-accessibility" and
-  // "disable-renderer-accessibility".
-  if (accessibility_state == STATE_DEFAULT)
-    return;
-
-  content::WebContentsImpl* web_contents_impl =
-      static_cast<content::WebContentsImpl*>(web_contents_);
-
-  if (!web_contents_impl)
-    return;
-
-  ui::AXMode accMode;
-  // In windowless mode set accessibility to TreeOnly mode. Else native
-  // accessibility APIs, specific to each platform, are also created.
-  if (accessibility_state == STATE_ENABLED) {
-    accMode = IsWindowless() ? ui::kAXModeWebContentsOnly : ui::kAXModeComplete;
-  }
-  web_contents_impl->SetAccessibilityMode(accMode);
+  NOTIMPLEMENTED();
 }
 
 bool CefBrowserPlatformDelegate::IsPrintPreviewSupported() const {
-  CEF_REQUIRE_UIT();
-  auto actionable_contents = GetActionableWebContents();
-  if (!actionable_contents)
-    return false;
-
-  auto cef_browser_context = CefBrowserContext::FromBrowserContext(
-      actionable_contents->GetBrowserContext());
-  if (!cef_browser_context->IsPrintPreviewSupported()) {
-    return false;
-  }
-
-  // Print preview is not currently supported with OSR.
-  return !IsWindowless();
+  return true;
 }
 
 void CefBrowserPlatformDelegate::Print() {
-  auto actionable_contents = GetActionableWebContents();
-  if (!actionable_contents)
-    return;
-
-  auto rfh = actionable_contents->GetMainFrame();
-
-  if (IsPrintPreviewSupported()) {
-    printing::CefPrintViewManager::FromWebContents(actionable_contents)
-        ->PrintPreviewNow(rfh, false);
-  } else {
-    printing::PrintViewManager::FromWebContents(actionable_contents)
-        ->PrintNow(rfh);
-  }
+  NOTIMPLEMENTED();
 }
 
 void CefBrowserPlatformDelegate::PrintToPDF(
     const CefString& path,
     const CefPdfPrintSettings& settings,
     CefRefPtr<CefPdfPrintCallback> callback) {
-  content::WebContents* actionable_contents = GetActionableWebContents();
-  if (!actionable_contents)
-    return;
-  printing::CefPrintViewManager::PdfPrintCallback pdf_callback;
-  if (callback.get()) {
-    pdf_callback = base::Bind(&CefPdfPrintCallback::OnPdfPrintFinished,
-                              callback.get(), path);
-  }
-  printing::CefPrintViewManager::FromWebContents(actionable_contents)
-      ->PrintToPDF(actionable_contents->GetMainFrame(), base::FilePath(path),
-                   settings, pdf_callback);
+  NOTIMPLEMENTED();
 }
 
 void CefBrowserPlatformDelegate::Find(int identifier,
@@ -527,40 +298,11 @@ void CefBrowserPlatformDelegate::Find(int identifier,
                                       bool forward,
                                       bool matchCase,
                                       bool findNext) {
-  if (!web_contents_)
-    return;
-
-  // Every find request must have a unique ID and these IDs must strictly
-  // increase so that newer requests always have greater IDs than older
-  // requests.
-  if (identifier <= find_request_id_counter_)
-    identifier = ++find_request_id_counter_;
-  else
-    find_request_id_counter_ = identifier;
-
-  auto options = blink::mojom::FindOptions::New();
-  options->forward = forward;
-  options->match_case = matchCase;
-  options->find_next = findNext;
-  web_contents_->Find(identifier, searchText, std::move(options));
+  NOTIMPLEMENTED();
 }
 
 void CefBrowserPlatformDelegate::StopFinding(bool clearSelection) {
-  if (!web_contents_)
-    return;
-
-  content::StopFindAction action =
-      clearSelection ? content::STOP_FIND_ACTION_CLEAR_SELECTION
-                     : content::STOP_FIND_ACTION_KEEP_SELECTION;
-  web_contents_->StopFinding(action);
-}
-
-base::RepeatingClosure CefBrowserPlatformDelegate::GetBoundsChangedCallback() {
-  if (web_contents_dialog_helper_) {
-    return web_contents_dialog_helper_->GetBoundsChangedCallback();
-  }
-
-  return base::RepeatingClosure();
+  NOTIMPLEMENTED();
 }
 
 // static
@@ -594,48 +336,3 @@ int CefBrowserPlatformDelegate::TranslateWebEventModifiers(
     result |= blink::WebInputEvent::kIsKeyPad;
   return result;
 }
-
-content::WebContents* CefBrowserPlatformDelegate::GetActionableWebContents()
-    const {
-  if (web_contents_ && extensions::ExtensionsEnabled()) {
-    content::WebContents* guest_contents =
-        extensions::GetFullPageGuestForOwnerContents(web_contents_);
-    if (guest_contents)
-      return guest_contents;
-  }
-  return web_contents_;
-}
-
-void CefBrowserPlatformDelegate::SetOwnedWebContents(
-    content::WebContents* owned_contents) {
-  REQUIRE_ALLOY_RUNTIME();
-
-  // Should not currently own a WebContents.
-  CHECK(!owned_web_contents_);
-  owned_web_contents_.reset(owned_contents);
-}
-
-void CefBrowserPlatformDelegate::DestroyExtensionHost() {
-  if (!extension_host_)
-    return;
-  if (extension_host_->extension_host_type() ==
-      extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
-    DCHECK(is_background_host_);
-    // Close notification for background pages arrives via CloseContents.
-    // The extension host will be deleted by
-    // ProcessManager::CloseBackgroundHost and OnExtensionHostDeleted will be
-    // called to notify us.
-    extension_host_->Close();
-  } else {
-    DCHECK(!is_background_host_);
-    // We own the extension host and must delete it.
-    delete extension_host_;
-    extension_host_ = nullptr;
-  }
-}
-
-void CefBrowserPlatformDelegate::OnExtensionHostDeleted() {
-  DCHECK(is_background_host_);
-  DCHECK(extension_host_);
-  extension_host_ = nullptr;
-}
diff --git a/libcef/browser/browser_platform_delegate.h b/libcef/browser/browser_platform_delegate.h
index 1282afd56..0e269498c 100644
--- a/libcef/browser/browser_platform_delegate.h
+++ b/libcef/browser/browser_platform_delegate.h
@@ -16,7 +16,6 @@
 #include "libcef/browser/browser_host_impl.h"
 
 #include "base/callback_forward.h"
-#include "base/memory/weak_ptr.h"
 #include "content/public/browser/web_contents.h"
 
 namespace blink {
@@ -43,11 +42,9 @@ class Widget;
 }
 #endif
 
-class CefBrowserInfo;
 class CefFileDialogRunner;
 class CefJavaScriptDialogRunner;
 class CefMenuRunner;
-class CefWebContentsDialogHelper;
 
 // Provides platform-specific implementations of browser functionality. All
 // methods are called on the browser process UI thread unless otherwise
@@ -64,7 +61,7 @@ class CefBrowserPlatformDelegate {
   // of the resulting WebContents object.
   virtual content::WebContents* CreateWebContents(
       CefBrowserHostImpl::CreateParams& create_params,
-      bool& own_web_contents);
+      bool& own_web_contents) = 0;
 
   // Called to create the view objects for a new WebContents. Will only be
   // called a single time per instance. May be called on multiple threads. Only
@@ -103,15 +100,21 @@ class CefBrowserPlatformDelegate {
   // Called after the RenderViewHost is created.
   virtual void RenderViewCreated(content::RenderViewHost* render_view_host);
 
+  // See WebContentsObserver documentation.
+  virtual void RenderViewReady();
+
   // Called after the owning CefBrowserHostImpl is created. Will only be called
   // a single time per instance. Do not send any client notifications from this
   // method.
   virtual void BrowserCreated(CefBrowserHostImpl* browser);
 
   // Called from CefBrowserHostImpl::Create.
-  void CreateExtensionHost(const extensions::Extension* extension,
-                           const GURL& url,
-                           extensions::ViewType host_type);
+  virtual void CreateExtensionHost(const extensions::Extension* extension,
+                                   const GURL& url,
+                                   extensions::ViewType host_type);
+
+  // Returns the current extension host.
+  virtual extensions::ExtensionHost* GetExtensionHost() const;
 
   // Send any notifications related to browser creation. Called after
   // BrowserCreated().
@@ -181,9 +184,6 @@ class CefBrowserPlatformDelegate {
   // enable transparency.
   virtual SkColor GetBackgroundColor() const = 0;
 
-  virtual bool CanUseSharedTexture() const = 0;
-  virtual bool CanUseExternalBeginFrame() const = 0;
-
   // Notify the window that it was resized.
   virtual void WasResized() = 0;
 
@@ -271,6 +271,7 @@ class CefBrowserPlatformDelegate {
   // Invalidate the view. Only used with windowless rendering.
   virtual void Invalidate(cef_paint_element_type_t type);
 
+  // Send the external begin frame message. Only used with windowless rendering.
   virtual void SendExternalBeginFrame();
 
   // Set the windowless frame rate. Only used with windowless rendering.
@@ -315,10 +316,9 @@ class CefBrowserPlatformDelegate {
   virtual gfx::Size GetMaximumDialogSize();
 
   // See CefBrowserHost documentation.
-  void SetAutoResizeEnabled(bool enabled,
-                            const CefSize& min_size,
-                            const CefSize& max_size);
-  virtual void ConfigureAutoResize();
+  virtual void SetAutoResizeEnabled(bool enabled,
+                                    const CefSize& min_size,
+                                    const CefSize& max_size);
   virtual void SetAccessibilityState(cef_state_t accessibility_state);
   virtual bool IsPrintPreviewSupported() const;
   virtual void Print();
@@ -332,8 +332,6 @@ class CefBrowserPlatformDelegate {
                     bool findNext);
   virtual void StopFinding(bool clearSelection);
 
-  extensions::ExtensionHost* extension_host() const { return extension_host_; }
-
  protected:
   // Allow deletion via scoped_ptr only.
   friend std::default_delete<CefBrowserPlatformDelegate>;
@@ -341,49 +339,12 @@ class CefBrowserPlatformDelegate {
   CefBrowserPlatformDelegate();
   virtual ~CefBrowserPlatformDelegate();
 
-  base::RepeatingClosure GetBoundsChangedCallback();
-
   static int TranslateWebEventModifiers(uint32 cef_modifiers);
 
-  // Returns the WebContents most likely to handle an action. If extensions are
-  // enabled and this browser has a full-page guest (for example, a full-page
-  // PDF viewer extension) then the guest's WebContents will be returned.
-  // Otherwise, the browser's WebContents will be returned.
-  content::WebContents* GetActionableWebContents() const;
-
   // Not owned by this object.
   content::WebContents* web_contents_ = nullptr;
   CefBrowserHostImpl* browser_ = nullptr;
 
- private:
-  void SetOwnedWebContents(content::WebContents* owned_contents);
-
-  void DestroyExtensionHost();
-  void OnExtensionHostDeleted();
-
-  // Non-nullptr if this object owns the WebContents. Will be nullptr for popup
-  // browsers between the calls to WebContentsCreated() and AddNewContents(),
-  // and may never be set if the parent browser is destroyed during popup
-  // creation.
-  std::unique_ptr<content::WebContents> owned_web_contents_;
-
-  // Used for the print preview dialog.
-  std::unique_ptr<CefWebContentsDialogHelper> web_contents_dialog_helper_;
-
-  // Used to provide unique incremental IDs for each find request.
-  int find_request_id_counter_ = 0;
-
-  // Used when the browser is hosting an extension.
-  extensions::ExtensionHost* extension_host_ = nullptr;
-  bool is_background_host_ = false;
-
-  // Used with auto-resize.
-  bool auto_resize_enabled_ = false;
-  gfx::Size auto_resize_min_;
-  gfx::Size auto_resize_max_;
-
-  base::WeakPtrFactory<CefBrowserPlatformDelegate> weak_ptr_factory_;
-
   DISALLOW_COPY_AND_ASSIGN(CefBrowserPlatformDelegate);
 };
 
diff --git a/libcef/browser/browser_platform_delegate_create.cc b/libcef/browser/browser_platform_delegate_create.cc
index 44364bbd8..954581e91 100644
--- a/libcef/browser/browser_platform_delegate_create.cc
+++ b/libcef/browser/browser_platform_delegate_create.cc
@@ -36,33 +36,32 @@ namespace {
 
 std::unique_ptr<CefBrowserPlatformDelegateNative> CreateNativeDelegate(
     const CefWindowInfo& window_info,
-    SkColor background_color,
-    bool use_shared_texture,
-    bool use_external_begin_frame) {
+    SkColor background_color) {
 #if defined(OS_WIN)
   return std::make_unique<CefBrowserPlatformDelegateNativeWin>(
-      window_info, background_color, use_shared_texture,
-      use_external_begin_frame);
+      window_info, background_color);
 #elif defined(OS_MACOSX)
   return std::make_unique<CefBrowserPlatformDelegateNativeMac>(
       window_info, background_color);
 #elif defined(OS_LINUX)
   return std::make_unique<CefBrowserPlatformDelegateNativeLinux>(
-      window_info, background_color, use_external_begin_frame);
+      window_info, background_color);
 #endif
 }
 
 std::unique_ptr<CefBrowserPlatformDelegateOsr> CreateOSRDelegate(
-    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate) {
+    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+    bool use_shared_texture,
+    bool use_external_begin_frame) {
 #if defined(OS_WIN)
   return std::make_unique<CefBrowserPlatformDelegateOsrWin>(
-      std::move(native_delegate));
+      std::move(native_delegate), use_shared_texture, use_external_begin_frame);
 #elif defined(OS_MACOSX)
   return std::make_unique<CefBrowserPlatformDelegateOsrMac>(
       std::move(native_delegate));
 #elif defined(OS_LINUX)
   return std::make_unique<CefBrowserPlatformDelegateOsrLinux>(
-      std::move(native_delegate));
+      std::move(native_delegate), use_external_begin_frame);
 #endif
 }
 
@@ -78,37 +77,34 @@ std::unique_ptr<CefBrowserPlatformDelegate> CefBrowserPlatformDelegate::Create(
   const SkColor background_color = CefContext::Get()->GetBackgroundColor(
       &create_params.settings, is_windowless ? STATE_ENABLED : STATE_DISABLED);
 
-  bool use_shared_texture = false;
-  bool use_external_begin_frame = false;
-
-  if (is_windowless) {
-    REQUIRE_ALLOY_RUNTIME();
-
-    use_shared_texture = create_params.window_info &&
-                         create_params.window_info->shared_texture_enabled;
-
-    use_external_begin_frame =
-        create_params.window_info &&
-        create_params.window_info->external_begin_frame_enabled;
-  }
-
   if (cef::IsChromeRuntimeEnabled()) {
     return std::make_unique<CefBrowserPlatformDelegateChrome>(background_color);
   }
 
   if (create_params.window_info) {
     std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate =
-        CreateNativeDelegate(*create_params.window_info.get(), background_color,
-                             use_shared_texture, use_external_begin_frame);
-    if (is_windowless)
-      return CreateOSRDelegate(std::move(native_delegate));
+        CreateNativeDelegate(*create_params.window_info.get(),
+                             background_color);
+    if (is_windowless) {
+      REQUIRE_ALLOY_RUNTIME();
+
+      const bool use_shared_texture =
+          create_params.window_info &&
+          create_params.window_info->shared_texture_enabled;
+
+      const bool use_external_begin_frame =
+          create_params.window_info &&
+          create_params.window_info->external_begin_frame_enabled;
+
+      return CreateOSRDelegate(std::move(native_delegate), use_shared_texture,
+                               use_external_begin_frame);
+    }
     return std::move(native_delegate);
   } else if (create_params.extension_host_type ==
              extensions::VIEW_TYPE_EXTENSION_BACKGROUND_PAGE) {
     // Creating a background extension host without a window.
     std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate =
-        CreateNativeDelegate(CefWindowInfo(), background_color,
-                             use_shared_texture, use_external_begin_frame);
+        CreateNativeDelegate(CefWindowInfo(), background_color);
     return std::make_unique<CefBrowserPlatformDelegateBackground>(
         std::move(native_delegate));
   }
@@ -116,8 +112,7 @@ std::unique_ptr<CefBrowserPlatformDelegate> CefBrowserPlatformDelegate::Create(
   else {
     // CefWindowInfo is not used in this case.
     std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate =
-        CreateNativeDelegate(CefWindowInfo(), background_color,
-                             use_shared_texture, use_external_begin_frame);
+        CreateNativeDelegate(CefWindowInfo(), background_color);
     return std::make_unique<CefBrowserPlatformDelegateViews>(
         std::move(native_delegate),
         static_cast<CefBrowserViewImpl*>(create_params.browser_view.get()));
diff --git a/libcef/browser/chrome/browser_platform_delegate_chrome.cc b/libcef/browser/chrome/browser_platform_delegate_chrome.cc
index 53a8c2be8..a8bd9a249 100644
--- a/libcef/browser/chrome/browser_platform_delegate_chrome.cc
+++ b/libcef/browser/chrome/browser_platform_delegate_chrome.cc
@@ -4,6 +4,7 @@
 
 #include "libcef/browser/chrome/browser_platform_delegate_chrome.h"
 
+#include "base/logging.h"
 #include "chrome/browser/ui/browser.h"
 #include "chrome/browser/ui/browser_tabstrip.h"
 #include "chrome/browser/ui/browser_window.h"
@@ -81,14 +82,6 @@ SkColor CefBrowserPlatformDelegateChrome::GetBackgroundColor() const {
   return background_color_;
 }
 
-bool CefBrowserPlatformDelegateChrome::CanUseSharedTexture() const {
-  return false;
-}
-
-bool CefBrowserPlatformDelegateChrome::CanUseExternalBeginFrame() const {
-  return false;
-}
-
 void CefBrowserPlatformDelegateChrome::WasResized() {}
 
 void CefBrowserPlatformDelegateChrome::SendKeyEvent(const CefKeyEvent& event) {}
@@ -132,6 +125,7 @@ CefEventHandle CefBrowserPlatformDelegateChrome::GetEventHandle(
 
 std::unique_ptr<CefMenuRunner>
 CefBrowserPlatformDelegateChrome::CreateMenuRunner() {
+  NOTIMPLEMENTED();
   return nullptr;
 }
 
diff --git a/libcef/browser/chrome/browser_platform_delegate_chrome.h b/libcef/browser/chrome/browser_platform_delegate_chrome.h
index 581442d19..a19855b97 100644
--- a/libcef/browser/chrome/browser_platform_delegate_chrome.h
+++ b/libcef/browser/chrome/browser_platform_delegate_chrome.h
@@ -24,8 +24,6 @@ class CefBrowserPlatformDelegateChrome : public CefBrowserPlatformDelegate {
   void CloseHostWindow() override;
   CefWindowHandle GetHostWindowHandle() const override;
   SkColor GetBackgroundColor() const override;
-  bool CanUseSharedTexture() const override;
-  bool CanUseExternalBeginFrame() const override;
   void WasResized() override;
   void SendKeyEvent(const CefKeyEvent& event) override;
   void SendMouseClickEvent(const CefMouseEvent& event,
diff --git a/libcef/browser/extensions/browser_platform_delegate_background.cc b/libcef/browser/extensions/browser_platform_delegate_background.cc
index ac542b9bf..ca3d80cae 100644
--- a/libcef/browser/extensions/browser_platform_delegate_background.cc
+++ b/libcef/browser/extensions/browser_platform_delegate_background.cc
@@ -35,14 +35,6 @@ CefWindowHandle CefBrowserPlatformDelegateBackground::GetHostWindowHandle()
   return kNullWindowHandle;
 }
 
-bool CefBrowserPlatformDelegateBackground::CanUseSharedTexture() const {
-  return native_delegate_->CanUseSharedTexture();
-}
-
-bool CefBrowserPlatformDelegateBackground::CanUseExternalBeginFrame() const {
-  return native_delegate_->CanUseExternalBeginFrame();
-}
-
 SkColor CefBrowserPlatformDelegateBackground::GetBackgroundColor() const {
   return native_delegate_->GetBackgroundColor();
 }
diff --git a/libcef/browser/extensions/browser_platform_delegate_background.h b/libcef/browser/extensions/browser_platform_delegate_background.h
index 2ded3736c..2aaf2a055 100644
--- a/libcef/browser/extensions/browser_platform_delegate_background.h
+++ b/libcef/browser/extensions/browser_platform_delegate_background.h
@@ -5,12 +5,12 @@
 #ifndef CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_BACKGROUND_H_
 #define CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_BACKGROUND_H_
 
-#include "libcef/browser/browser_platform_delegate.h"
+#include "libcef/browser/alloy/browser_platform_delegate_alloy.h"
 #include "libcef/browser/native/browser_platform_delegate_native.h"
 
 // Implementation of browser functionality for background script hosts.
 class CefBrowserPlatformDelegateBackground
-    : public CefBrowserPlatformDelegate,
+    : public CefBrowserPlatformDelegateAlloy,
       public CefBrowserPlatformDelegateNative::WindowlessHandler {
  public:
   // Platform-specific behaviors will be delegated to |native_delegate|.
@@ -22,8 +22,6 @@ class CefBrowserPlatformDelegateBackground
   void CloseHostWindow() override;
   CefWindowHandle GetHostWindowHandle() const override;
   SkColor GetBackgroundColor() const override;
-  bool CanUseSharedTexture() const override;
-  bool CanUseExternalBeginFrame() const override;
   void WasResized() override;
   void SendKeyEvent(const CefKeyEvent& event) override;
   void SendMouseClickEvent(const CefMouseEvent& event,
diff --git a/libcef/browser/native/browser_platform_delegate_native.cc b/libcef/browser/native/browser_platform_delegate_native.cc
index b26ee3e1f..0fb83cf01 100644
--- a/libcef/browser/native/browser_platform_delegate_native.cc
+++ b/libcef/browser/native/browser_platform_delegate_native.cc
@@ -12,27 +12,15 @@
 
 CefBrowserPlatformDelegateNative::CefBrowserPlatformDelegateNative(
     const CefWindowInfo& window_info,
-    SkColor background_color,
-    bool use_shared_texture,
-    bool use_external_begin_frame)
+    SkColor background_color)
     : window_info_(window_info),
       background_color_(background_color),
-      use_shared_texture_(use_shared_texture),
-      use_external_begin_frame_(use_external_begin_frame),
       windowless_handler_(nullptr) {}
 
 SkColor CefBrowserPlatformDelegateNative::GetBackgroundColor() const {
   return background_color_;
 }
 
-bool CefBrowserPlatformDelegateNative::CanUseSharedTexture() const {
-  return use_shared_texture_;
-}
-
-bool CefBrowserPlatformDelegateNative::CanUseExternalBeginFrame() const {
-  return use_external_begin_frame_;
-}
-
 void CefBrowserPlatformDelegateNative::WasResized() {
   content::RenderViewHost* host = browser_->web_contents()->GetRenderViewHost();
   if (host)
diff --git a/libcef/browser/native/browser_platform_delegate_native.h b/libcef/browser/native/browser_platform_delegate_native.h
index a7c3003ca..e3e608818 100644
--- a/libcef/browser/native/browser_platform_delegate_native.h
+++ b/libcef/browser/native/browser_platform_delegate_native.h
@@ -5,10 +5,11 @@
 #ifndef CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_H_
 #define CEF_LIBCEF_BROWSER_NATIVE_BROWSER_PLATFORM_DELEGATE_NATIVE_H_
 
-#include "libcef/browser/browser_platform_delegate.h"
+#include "libcef/browser/alloy/browser_platform_delegate_alloy.h"
 
 // Base implementation of native browser functionality.
-class CefBrowserPlatformDelegateNative : public CefBrowserPlatformDelegate {
+class CefBrowserPlatformDelegateNative
+    : public CefBrowserPlatformDelegateAlloy {
  public:
   // Used by the windowless implementation to override specific functionality
   // when delegating to the native implementation.
@@ -25,8 +26,6 @@ class CefBrowserPlatformDelegateNative : public CefBrowserPlatformDelegate {
   };
 
   // CefBrowserPlatformDelegate methods:
-  bool CanUseSharedTexture() const override;
-  bool CanUseExternalBeginFrame() const override;
   SkColor GetBackgroundColor() const override;
   void WasResized() override;
   bool IsWindowless() const override;
@@ -57,9 +56,7 @@ class CefBrowserPlatformDelegateNative : public CefBrowserPlatformDelegate {
   friend class CefBrowserPlatformDelegateViews;
 
   CefBrowserPlatformDelegateNative(const CefWindowInfo& window_info,
-                                   SkColor background_color,
-                                   bool use_shared_texture,
-                                   bool use_external_begin_frame);
+                                   SkColor background_color);
 
   // Methods used by delegates that can wrap a native delegate.
   void set_windowless_handler(WindowlessHandler* handler) {
@@ -69,8 +66,6 @@ class CefBrowserPlatformDelegateNative : public CefBrowserPlatformDelegate {
 
   CefWindowInfo window_info_;
   const SkColor background_color_;
-  const bool use_shared_texture_;
-  const bool use_external_begin_frame_;
 
   WindowlessHandler* windowless_handler_;  // Not owned by this object.
 };
diff --git a/libcef/browser/native/browser_platform_delegate_native_aura.cc b/libcef/browser/native/browser_platform_delegate_native_aura.cc
index db5ceb1ea..e9f5a1d24 100644
--- a/libcef/browser/native/browser_platform_delegate_native_aura.cc
+++ b/libcef/browser/native/browser_platform_delegate_native_aura.cc
@@ -13,13 +13,8 @@
 
 CefBrowserPlatformDelegateNativeAura::CefBrowserPlatformDelegateNativeAura(
     const CefWindowInfo& window_info,
-    SkColor background_color,
-    bool use_shared_texture,
-    bool use_external_begin_frame)
-    : CefBrowserPlatformDelegateNative(window_info,
-                                       background_color,
-                                       use_shared_texture,
-                                       use_external_begin_frame) {}
+    SkColor background_color)
+    : CefBrowserPlatformDelegateNative(window_info, background_color) {}
 
 void CefBrowserPlatformDelegateNativeAura::SendKeyEvent(
     const CefKeyEvent& event) {
diff --git a/libcef/browser/native/browser_platform_delegate_native_aura.h b/libcef/browser/native/browser_platform_delegate_native_aura.h
index 96b5a41d7..63d9546b8 100644
--- a/libcef/browser/native/browser_platform_delegate_native_aura.h
+++ b/libcef/browser/native/browser_platform_delegate_native_aura.h
@@ -22,9 +22,7 @@ class CefBrowserPlatformDelegateNativeAura
     : public CefBrowserPlatformDelegateNative {
  public:
   CefBrowserPlatformDelegateNativeAura(const CefWindowInfo& window_info,
-                                       SkColor background_color,
-                                       bool use_shared_texture,
-                                       bool use_external_begin_frame);
+                                       SkColor background_color);
 
   // CefBrowserPlatformDelegate methods:
   void SendKeyEvent(const CefKeyEvent& event) override;
diff --git a/libcef/browser/native/browser_platform_delegate_native_linux.cc b/libcef/browser/native/browser_platform_delegate_native_linux.cc
index b6364b2f0..2784d30e5 100644
--- a/libcef/browser/native/browser_platform_delegate_native_linux.cc
+++ b/libcef/browser/native/browser_platform_delegate_native_linux.cc
@@ -44,18 +44,14 @@ long GetSystemUptime() {
 
 CefBrowserPlatformDelegateNativeLinux::CefBrowserPlatformDelegateNativeLinux(
     const CefWindowInfo& window_info,
-    SkColor background_color,
-    bool use_external_begin_frame)
-    : CefBrowserPlatformDelegateNativeAura(window_info,
-                                           background_color,
-                                           false,
-                                           use_external_begin_frame),
+    SkColor background_color)
+    : CefBrowserPlatformDelegateNativeAura(window_info, background_color),
       host_window_created_(false),
       window_widget_(nullptr) {}
 
 void CefBrowserPlatformDelegateNativeLinux::BrowserDestroyed(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserDestroyed(browser);
+  CefBrowserPlatformDelegateNative::BrowserDestroyed(browser);
 
   if (host_window_created_) {
     // Release the reference added in CreateHostWindow().
@@ -166,7 +162,7 @@ void CefBrowserPlatformDelegateNativeLinux::SendFocusEvent(bool setFocus) {
 
 void CefBrowserPlatformDelegateNativeLinux::NotifyMoveOrResizeStarted() {
   // Call the parent method to dismiss any existing popups.
-  CefBrowserPlatformDelegate::NotifyMoveOrResizeStarted();
+  CefBrowserPlatformDelegateNative::NotifyMoveOrResizeStarted();
 
 #if defined(USE_X11)
   if (!window_x11_)
diff --git a/libcef/browser/native/browser_platform_delegate_native_linux.h b/libcef/browser/native/browser_platform_delegate_native_linux.h
index 7f1834a3d..cb8a235c2 100644
--- a/libcef/browser/native/browser_platform_delegate_native_linux.h
+++ b/libcef/browser/native/browser_platform_delegate_native_linux.h
@@ -16,8 +16,7 @@ class CefBrowserPlatformDelegateNativeLinux
     : public CefBrowserPlatformDelegateNativeAura {
  public:
   CefBrowserPlatformDelegateNativeLinux(const CefWindowInfo& window_info,
-                                        SkColor background_color,
-                                        bool use_external_begin_frame);
+                                        SkColor background_color);
 
   // CefBrowserPlatformDelegate methods:
   void BrowserDestroyed(CefBrowserHostImpl* browser) override;
diff --git a/libcef/browser/native/browser_platform_delegate_native_mac.mm b/libcef/browser/native/browser_platform_delegate_native_mac.mm
index 34569ca82..9dc266618 100644
--- a/libcef/browser/native/browser_platform_delegate_native_mac.mm
+++ b/libcef/browser/native/browser_platform_delegate_native_mac.mm
@@ -146,15 +146,12 @@ NSUInteger NativeModifiers(int cef_modifiers) {
 CefBrowserPlatformDelegateNativeMac::CefBrowserPlatformDelegateNativeMac(
     const CefWindowInfo& window_info,
     SkColor background_color)
-    : CefBrowserPlatformDelegateNative(window_info,
-                                       background_color,
-                                       false,
-                                       false),
+    : CefBrowserPlatformDelegateNative(window_info, background_color),
       host_window_created_(false) {}
 
 void CefBrowserPlatformDelegateNativeMac::BrowserDestroyed(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserDestroyed(browser);
+  CefBrowserPlatformDelegateNative::BrowserDestroyed(browser);
 
   if (host_window_created_) {
     // Release the reference added in CreateHostWindow().
diff --git a/libcef/browser/native/browser_platform_delegate_native_win.cc b/libcef/browser/native/browser_platform_delegate_native_win.cc
index 4c923c971..23e9ee2d1 100644
--- a/libcef/browser/native/browser_platform_delegate_native_win.cc
+++ b/libcef/browser/native/browser_platform_delegate_native_win.cc
@@ -126,19 +126,14 @@ float GetWindowScaleFactor(HWND hwnd) {
 
 CefBrowserPlatformDelegateNativeWin::CefBrowserPlatformDelegateNativeWin(
     const CefWindowInfo& window_info,
-    SkColor background_color,
-    bool use_shared_texture,
-    bool use_external_begin_frame)
-    : CefBrowserPlatformDelegateNativeAura(window_info,
-                                           background_color,
-                                           use_shared_texture,
-                                           use_external_begin_frame),
+    SkColor background_color)
+    : CefBrowserPlatformDelegateNativeAura(window_info, background_color),
       host_window_created_(false),
       window_widget_(nullptr) {}
 
 void CefBrowserPlatformDelegateNativeWin::BrowserDestroyed(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserDestroyed(browser);
+  CefBrowserPlatformDelegateNative::BrowserDestroyed(browser);
 
   if (host_window_created_) {
     // Release the reference added in CreateHostWindow().
@@ -295,7 +290,7 @@ void CefBrowserPlatformDelegateNativeWin::SendFocusEvent(bool setFocus) {
 
 void CefBrowserPlatformDelegateNativeWin::NotifyMoveOrResizeStarted() {
   // Call the parent method to dismiss any existing popups.
-  CefBrowserPlatformDelegate::NotifyMoveOrResizeStarted();
+  CefBrowserPlatformDelegateNative::NotifyMoveOrResizeStarted();
 
   if (!window_widget_)
     return;
diff --git a/libcef/browser/native/browser_platform_delegate_native_win.h b/libcef/browser/native/browser_platform_delegate_native_win.h
index e1dd0a097..c2ab6b3cc 100644
--- a/libcef/browser/native/browser_platform_delegate_native_win.h
+++ b/libcef/browser/native/browser_platform_delegate_native_win.h
@@ -14,9 +14,7 @@ class CefBrowserPlatformDelegateNativeWin
     : public CefBrowserPlatformDelegateNativeAura {
  public:
   CefBrowserPlatformDelegateNativeWin(const CefWindowInfo& window_info,
-                                      SkColor background_color,
-                                      bool use_shared_texture,
-                                      bool use_external_begin_frame);
+                                      SkColor background_color);
 
   // CefBrowserPlatformDelegate methods:
   void BrowserDestroyed(CefBrowserHostImpl* browser) override;
diff --git a/libcef/browser/osr/browser_platform_delegate_osr.cc b/libcef/browser/osr/browser_platform_delegate_osr.cc
index 829ae8b63..22d01b9ec 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr.cc
+++ b/libcef/browser/osr/browser_platform_delegate_osr.cc
@@ -20,8 +20,12 @@
 #include "ui/events/base_event_utils.h"
 
 CefBrowserPlatformDelegateOsr::CefBrowserPlatformDelegateOsr(
-    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate)
-    : native_delegate_(std::move(native_delegate)), view_osr_(nullptr) {
+    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+    bool use_shared_texture,
+    bool use_external_begin_frame)
+    : native_delegate_(std::move(native_delegate)),
+      use_shared_texture_(use_shared_texture),
+      use_external_begin_frame_(use_external_begin_frame) {
   native_delegate_->set_windowless_handler(this);
 }
 
@@ -32,7 +36,7 @@ void CefBrowserPlatformDelegateOsr::CreateViewForWebContents(
 
   // Use the OSR view instead of the default platform view.
   view_osr_ = new CefWebContentsViewOSR(
-      GetBackgroundColor(), CanUseSharedTexture(), CanUseExternalBeginFrame());
+      GetBackgroundColor(), use_shared_texture_, use_external_begin_frame_);
   *view = view_osr_;
   *delegate_view = view_osr_;
 }
@@ -40,7 +44,7 @@ void CefBrowserPlatformDelegateOsr::CreateViewForWebContents(
 void CefBrowserPlatformDelegateOsr::WebContentsCreated(
     content::WebContents* web_contents,
     bool owned) {
-  CefBrowserPlatformDelegate::WebContentsCreated(web_contents, owned);
+  CefBrowserPlatformDelegateAlloy::WebContentsCreated(web_contents, owned);
 
   DCHECK(view_osr_);
   DCHECK(!view_osr_->web_contents());
@@ -51,7 +55,7 @@ void CefBrowserPlatformDelegateOsr::WebContentsCreated(
 
 void CefBrowserPlatformDelegateOsr::BrowserCreated(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserCreated(browser);
+  CefBrowserPlatformDelegateAlloy::BrowserCreated(browser);
 
   if (browser->IsPopup()) {
     // Associate the RenderWidget host view with the browser now because the
@@ -69,19 +73,11 @@ void CefBrowserPlatformDelegateOsr::BrowserCreated(
 
 void CefBrowserPlatformDelegateOsr::BrowserDestroyed(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserDestroyed(browser);
+  CefBrowserPlatformDelegateAlloy::BrowserDestroyed(browser);
 
   view_osr_ = nullptr;
 }
 
-bool CefBrowserPlatformDelegateOsr::CanUseSharedTexture() const {
-  return native_delegate_->CanUseSharedTexture();
-}
-
-bool CefBrowserPlatformDelegateOsr::CanUseExternalBeginFrame() const {
-  return native_delegate_->CanUseExternalBeginFrame();
-}
-
 SkColor CefBrowserPlatformDelegateOsr::GetBackgroundColor() const {
   return native_delegate_->GetBackgroundColor();
 }
diff --git a/libcef/browser/osr/browser_platform_delegate_osr.h b/libcef/browser/osr/browser_platform_delegate_osr.h
index 4dc3fcd44..6537915b4 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr.h
+++ b/libcef/browser/osr/browser_platform_delegate_osr.h
@@ -5,7 +5,7 @@
 #ifndef CEF_LIBCEF_BROWSER_OSR_BROWSER_PLATFORM_DELEGATE_OSR_H_
 #define CEF_LIBCEF_BROWSER_OSR_BROWSER_PLATFORM_DELEGATE_OSR_H_
 
-#include "libcef/browser/browser_platform_delegate.h"
+#include "libcef/browser/alloy/browser_platform_delegate_alloy.h"
 #include "libcef/browser/native/browser_platform_delegate_native.h"
 
 class CefRenderWidgetHostViewOSR;
@@ -17,7 +17,7 @@ class RenderWidgetHostImpl;
 
 // Base implementation of windowless browser functionality.
 class CefBrowserPlatformDelegateOsr
-    : public CefBrowserPlatformDelegate,
+    : public CefBrowserPlatformDelegateAlloy,
       public CefBrowserPlatformDelegateNative::WindowlessHandler {
  public:
   // CefBrowserPlatformDelegate methods:
@@ -29,8 +29,6 @@ class CefBrowserPlatformDelegateOsr
   void BrowserCreated(CefBrowserHostImpl* browser) override;
   void BrowserDestroyed(CefBrowserHostImpl* browser) override;
   SkColor GetBackgroundColor() const override;
-  bool CanUseSharedTexture() const override;
-  bool CanUseExternalBeginFrame() const override;
   void WasResized() override;
   void SendKeyEvent(const CefKeyEvent& event) override;
   void SendMouseClickEvent(const CefMouseEvent& event,
@@ -97,8 +95,10 @@ class CefBrowserPlatformDelegateOsr
 
  protected:
   // Platform-specific behaviors will be delegated to |native_delegate|.
-  explicit CefBrowserPlatformDelegateOsr(
-      std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate);
+  CefBrowserPlatformDelegateOsr(
+      std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+      bool use_shared_texture,
+      bool use_external_begin_frame);
 
   // Returns the primary OSR host view for the underlying browser. If a
   // full-screen host view currently exists then it will be returned. Otherwise,
@@ -106,7 +106,10 @@ class CefBrowserPlatformDelegateOsr
   CefRenderWidgetHostViewOSR* GetOSRHostView() const;
 
   std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate_;
-  CefWebContentsViewOSR* view_osr_;  // Not owned by this class.
+  const bool use_shared_texture_;
+  const bool use_external_begin_frame_;
+
+  CefWebContentsViewOSR* view_osr_ = nullptr;  // Not owned by this class.
 
   // Pending drag/drop data.
   CefRefPtr<CefDragData> drag_data_;
diff --git a/libcef/browser/osr/browser_platform_delegate_osr_linux.cc b/libcef/browser/osr/browser_platform_delegate_osr_linux.cc
index fda16ef30..2f7fef111 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr_linux.cc
+++ b/libcef/browser/osr/browser_platform_delegate_osr_linux.cc
@@ -9,8 +9,11 @@
 #include "libcef/browser/browser_host_impl.h"
 
 CefBrowserPlatformDelegateOsrLinux::CefBrowserPlatformDelegateOsrLinux(
-    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate)
-    : CefBrowserPlatformDelegateOsr(std::move(native_delegate)) {}
+    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+    bool use_external_begin_frame)
+    : CefBrowserPlatformDelegateOsr(std::move(native_delegate),
+                                    /*use_shared_texture=*/false,
+                                    use_external_begin_frame) {}
 
 CefWindowHandle CefBrowserPlatformDelegateOsrLinux::GetHostWindowHandle()
     const {
diff --git a/libcef/browser/osr/browser_platform_delegate_osr_linux.h b/libcef/browser/osr/browser_platform_delegate_osr_linux.h
index 4dc86ff3d..071a2cdd4 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr_linux.h
+++ b/libcef/browser/osr/browser_platform_delegate_osr_linux.h
@@ -11,8 +11,9 @@
 class CefBrowserPlatformDelegateOsrLinux
     : public CefBrowserPlatformDelegateOsr {
  public:
-  explicit CefBrowserPlatformDelegateOsrLinux(
-      std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate);
+  CefBrowserPlatformDelegateOsrLinux(
+      std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+      bool use_external_begin_frame);
 
   // CefBrowserPlatformDelegate methods:
   CefWindowHandle GetHostWindowHandle() const override;
diff --git a/libcef/browser/osr/browser_platform_delegate_osr_mac.mm b/libcef/browser/osr/browser_platform_delegate_osr_mac.mm
index a1f4afe4f..a2fa7b268 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr_mac.mm
+++ b/libcef/browser/osr/browser_platform_delegate_osr_mac.mm
@@ -11,7 +11,9 @@
 
 CefBrowserPlatformDelegateOsrMac::CefBrowserPlatformDelegateOsrMac(
     std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate)
-    : CefBrowserPlatformDelegateOsr(std::move(native_delegate)) {}
+    : CefBrowserPlatformDelegateOsr(std::move(native_delegate),
+                                    /*use_shared_texture=*/false,
+                                    /*use_external_begin_frame=*/false) {}
 
 CefWindowHandle CefBrowserPlatformDelegateOsrMac::GetHostWindowHandle() const {
   return native_delegate_->window_info().parent_view;
diff --git a/libcef/browser/osr/browser_platform_delegate_osr_win.cc b/libcef/browser/osr/browser_platform_delegate_osr_win.cc
index c09e79ccd..b9f624c31 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr_win.cc
+++ b/libcef/browser/osr/browser_platform_delegate_osr_win.cc
@@ -9,8 +9,12 @@
 #include "libcef/browser/browser_host_impl.h"
 
 CefBrowserPlatformDelegateOsrWin::CefBrowserPlatformDelegateOsrWin(
-    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate)
-    : CefBrowserPlatformDelegateOsr(std::move(native_delegate)) {}
+    std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+    bool use_shared_texture,
+    bool use_external_begin_frame)
+    : CefBrowserPlatformDelegateOsr(std::move(native_delegate),
+                                    use_shared_texture,
+                                    use_external_begin_frame) {}
 
 CefWindowHandle CefBrowserPlatformDelegateOsrWin::GetHostWindowHandle() const {
   return native_delegate_->window_info().parent_window;
diff --git a/libcef/browser/osr/browser_platform_delegate_osr_win.h b/libcef/browser/osr/browser_platform_delegate_osr_win.h
index bcc9d8b86..8c07a1530 100644
--- a/libcef/browser/osr/browser_platform_delegate_osr_win.h
+++ b/libcef/browser/osr/browser_platform_delegate_osr_win.h
@@ -11,7 +11,9 @@
 class CefBrowserPlatformDelegateOsrWin : public CefBrowserPlatformDelegateOsr {
  public:
   explicit CefBrowserPlatformDelegateOsrWin(
-      std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate);
+      std::unique_ptr<CefBrowserPlatformDelegateNative> native_delegate,
+      bool use_shared_texture,
+      bool use_external_begin_frame);
 
   // CefBrowserPlatformDelegate methods:
   CefWindowHandle GetHostWindowHandle() const override;
diff --git a/libcef/browser/views/browser_platform_delegate_views.cc b/libcef/browser/views/browser_platform_delegate_views.cc
index ae4b615b9..e7bb11ff4 100644
--- a/libcef/browser/views/browser_platform_delegate_views.cc
+++ b/libcef/browser/views/browser_platform_delegate_views.cc
@@ -68,14 +68,14 @@ void CefBrowserPlatformDelegateViews::SetBrowserView(
 void CefBrowserPlatformDelegateViews::WebContentsCreated(
     content::WebContents* web_contents,
     bool owned) {
-  CefBrowserPlatformDelegate::WebContentsCreated(web_contents, owned);
+  CefBrowserPlatformDelegateAlloy::WebContentsCreated(web_contents, owned);
 
   browser_view_->WebContentsCreated(web_contents);
 }
 
 void CefBrowserPlatformDelegateViews::BrowserCreated(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserCreated(browser);
+  CefBrowserPlatformDelegateAlloy::BrowserCreated(browser);
 
   native_delegate_->set_browser(browser);
   browser_view_->BrowserCreated(browser, GetBoundsChangedCallback());
@@ -97,7 +97,7 @@ void CefBrowserPlatformDelegateViews::NotifyBrowserDestroyed() {
 
 void CefBrowserPlatformDelegateViews::BrowserDestroyed(
     CefBrowserHostImpl* browser) {
-  CefBrowserPlatformDelegate::BrowserDestroyed(browser);
+  CefBrowserPlatformDelegateAlloy::BrowserDestroyed(browser);
 
   native_delegate_->set_browser(nullptr);
   browser_view_->BrowserDestroyed(browser);
@@ -173,14 +173,6 @@ void CefBrowserPlatformDelegateViews::PopupBrowserCreated(
   }
 }
 
-bool CefBrowserPlatformDelegateViews::CanUseSharedTexture() const {
-  return native_delegate_->CanUseSharedTexture();
-}
-
-bool CefBrowserPlatformDelegateViews::CanUseExternalBeginFrame() const {
-  return native_delegate_->CanUseExternalBeginFrame();
-}
-
 SkColor CefBrowserPlatformDelegateViews::GetBackgroundColor() const {
   return native_delegate_->GetBackgroundColor();
 }
diff --git a/libcef/browser/views/browser_platform_delegate_views.h b/libcef/browser/views/browser_platform_delegate_views.h
index ce23f4c18..62d6904de 100644
--- a/libcef/browser/views/browser_platform_delegate_views.h
+++ b/libcef/browser/views/browser_platform_delegate_views.h
@@ -5,13 +5,13 @@
 #ifndef CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_VIEWS_H_
 #define CEF_LIBCEF_BROWSER_VIEWS_BROWSER_PLATFORM_DELEGATE_VIEWS_H_
 
-#include "libcef/browser/browser_platform_delegate.h"
+#include "libcef/browser/alloy/browser_platform_delegate_alloy.h"
 #include "libcef/browser/native/browser_platform_delegate_native.h"
 #include "libcef/browser/views/browser_view_impl.h"
 
 // Implementation of Views-based browser functionality.
 class CefBrowserPlatformDelegateViews
-    : public CefBrowserPlatformDelegate,
+    : public CefBrowserPlatformDelegateAlloy,
       public CefBrowserPlatformDelegateNative::WindowlessHandler {
  public:
   // Platform-specific behaviors will be delegated to |native_delegate|.
@@ -40,8 +40,6 @@ class CefBrowserPlatformDelegateViews
       bool is_devtools) override;
   void PopupBrowserCreated(CefBrowserHostImpl* new_browser,
                            bool is_devtools) override;
-  bool CanUseSharedTexture() const override;
-  bool CanUseExternalBeginFrame() const override;
   SkColor GetBackgroundColor() const override;
   void WasResized() override;
   void SendKeyEvent(const CefKeyEvent& event) override;