chrome: Add extension support for Alloy style browsers (see #3681)

This change adds minimal tabs API support for Alloy style browsers.
Clicking links in PDF documents now navigate as expected.

libcef/browser/chrome/extensions/chrome_extension_util.h

@@ -0,0 +1,26 @@
+// Copyright 2024 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.
+
+#ifndef CEF_LIBCEF_BROWSER_CHROME_EXTENSIONS_CHROME_EXTENSION_UTIL_H_
+#define CEF_LIBCEF_BROWSER_CHROME_EXTENSIONS_CHROME_EXTENSION_UTIL_H_
+#pragma once
+
+namespace content {
+class WebContents;
+}  // namespace content
+
+class Profile;
+
+namespace cef {
+
+// Same as ExtensionTabUtil::GetTabById but searching only Alloy style
+// CefBrowserHosts.
+bool GetAlloyTabById(int tab_id,
+                     Profile* profile,
+                     bool include_incognito,
+                     content::WebContents** contents);
+
+}  // namespace cef
+
+#endif  // CEF_LIBCEF_BROWSER_CHROME_EXTENSIONS_CHROME_EXTENSION_UTIL_H_