Clean up old Mojo types for mojom::MojoWebTestHelper

This CL cleans up old Mojo types for mojom::MojoWebTestHelper
with replacing MojoWebTestHelperRequest with PendingReceiver.

Bug: 955171
Change-Id: Iafe8dd63d07466aa56323307852b2d3e8665f6cd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1880233Reviewed-by: Kinuko Yasuda <kinuko@chromium.org>
Reviewed-by: Oksana Zhuravlova <oksamyt@chromium.org>
Commit-Queue: Julie Kim <jkim@igalia.com>
Cr-Commit-Position: refs/heads/master@{#709725}

content/shell/browser/web_test/web_test_content_browser_client.cc

@@ -41,6 +41,7 @@
 #include "content/test/mock_platform_notification_service.h"
 #include "device/bluetooth/test/fake_bluetooth.h"
 #include "gpu/config/gpu_switches.h"
+#include "mojo/public/cpp/bindings/pending_receiver.h"
 #include "services/service_manager/public/cpp/binder_registry.h"
 #include "url/origin.h"
 
@@ -49,9 +50,9 @@ namespace {
 
 WebTestContentBrowserClient* g_web_test_browser_client;
 
-void BindWebTestHelper(mojom::MojoWebTestHelperRequest request,
+void BindWebTestHelper(mojo::PendingReceiver<mojom::MojoWebTestHelper> receiver,
                        RenderFrameHost* render_frame_host) {
-  MojoWebTestHelper::Create(std::move(request));
+  MojoWebTestHelper::Create(std::move(receiver));
 }
 
 class TestOverlayWindow : public OverlayWindow {