chrome: cefclient: Add default handler for request tests (see issue #3444)

Support loading of request tests (e.g. http://tests/other_tests) inside default
browsers created via "New window" and "New incognito window" commands.

tests/cefclient/browser/default_client_handler.h

@@ -0,0 +1,61 @@
+// Copyright (c) 2023 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_TESTS_CEFCLIENT_BROWSER_DEFAULT_CLIENT_HANDLER_H_
+#define CEF_TESTS_CEFCLIENT_BROWSER_DEFAULT_CLIENT_HANDLER_H_
+#pragma once
+
+#include "include/cef_client.h"
+#include "include/wrapper/cef_resource_manager.h"
+
+namespace client {
+
+// Default client handler for unmanaged browser windows. Used with the Chrome
+// runtime only.
+class DefaultClientHandler : public CefClient,
+                             public CefRequestHandler,
+                             public CefResourceRequestHandler {
+ public:
+  DefaultClientHandler();
+
+  // CefClient methods
+  CefRefPtr<CefRequestHandler> GetRequestHandler() override { return this; }
+
+  // CefRequestHandler methods
+  CefRefPtr<CefResourceRequestHandler> GetResourceRequestHandler(
+      CefRefPtr<CefBrowser> browser,
+      CefRefPtr<CefFrame> frame,
+      CefRefPtr<CefRequest> request,
+      bool is_navigation,
+      bool is_download,
+      const CefString& request_initiator,
+      bool& disable_default_handling) override;
+
+  // CefResourceRequestHandler methods
+  cef_return_value_t OnBeforeResourceLoad(
+      CefRefPtr<CefBrowser> browser,
+      CefRefPtr<CefFrame> frame,
+      CefRefPtr<CefRequest> request,
+      CefRefPtr<CefCallback> callback) override;
+  CefRefPtr<CefResourceHandler> GetResourceHandler(
+      CefRefPtr<CefBrowser> browser,
+      CefRefPtr<CefFrame> frame,
+      CefRefPtr<CefRequest> request) override;
+  CefRefPtr<CefResponseFilter> GetResourceResponseFilter(
+      CefRefPtr<CefBrowser> browser,
+      CefRefPtr<CefFrame> frame,
+      CefRefPtr<CefRequest> request,
+      CefRefPtr<CefResponse> response) override;
+
+ private:
+  // Manages the registration and delivery of resources.
+  CefRefPtr<CefResourceManager> resource_manager_;
+
+  IMPLEMENT_REFCOUNTING(DefaultClientHandler);
+  DISALLOW_COPY_AND_ASSIGN(DefaultClientHandler);
+};
+
+}  // namespace client
+
+#endif  // CEF_TESTS_CEFCLIENT_BROWSER_DEFAULT_CLIENT_HANDLER_H_