Update to Chromium version 86.0.4240.0 (#800218)

- CefURLRequest::Create is no longer supported in the renderer process
  (see https://crbug.com/891872). Use CefFrame::CreateURLRequest instead.
- Mac platform definitions have been changed from `MACOSX` to `MAC`
  (see https://crbug.com/1105907) and related CMake macro names have
  been updated. The old `OS_MACOSX` define is still set in code and CMake
  for backwards compatibility.
- Linux ARM build is currently broken (see https://crbug.com/1123214).

libcef/browser/alloy/alloy_content_browser_client.h

@@ -61,8 +61,6 @@ class AlloyContentBrowserClient : public content::ContentBrowserClient {
   void BindHostReceiverForRenderer(
       content::RenderProcessHost* render_process_host,
       mojo::GenericPendingReceiver receiver) override;
-  base::Optional<service_manager::Manifest> GetServiceManifestOverlay(
-      base::StringPiece name) override;
   void AppendExtraCommandLineSwitches(base::CommandLine* command_line,
                                       int child_process_id) override;
   std::string GetApplicationLocale() override;
@@ -149,6 +147,7 @@ class AlloyContentBrowserClient : public content::ContentBrowserClient {
       LoginAuthRequiredCallback auth_required_callback) override;
   void RegisterNonNetworkNavigationURLLoaderFactories(
       int frame_tree_node_id,
+      base::UkmSourceId ukm_source_id,
       NonNetworkURLLoaderFactoryMap* factories) override;
   void RegisterNonNetworkSubresourceURLLoaderFactories(
       int render_process_id,