refactor: return-braced-init-list pt 2 of 2 (#44891)

* refactor: more return-braced-init-list, this time for v8 and gin objects

Co-authored-by: Charles Kerr <charles@charleskerr.com>

* refactor: more return-braced-init-list, this time for v8, gin, std, and base objects

Co-authored-by: Charles Kerr <charles@charleskerr.com>

---------

Co-authored-by: trop[bot] <37223003+trop[bot]@users.noreply.github.com>
Co-authored-by: Charles Kerr <charles@charleskerr.com>

shell/browser/api/electron_api_data_pipe_holder.cc

@@ -188,7 +188,7 @@ gin::Handle<DataPipeHolder> DataPipeHolder::From(v8::Isolate* isolate,
     if (gin::ConvertFromV8(isolate, object.ToLocalChecked(), &handle))
       return handle;
   }
-  return gin::Handle<DataPipeHolder>();
+  return {};
 }
 
 }  // namespace electron::api

shell/browser/api/electron_api_download_item.cc

@@ -209,7 +209,7 @@ const GURL& DownloadItem::GetURL() const {
 
 v8::Local<v8::Value> DownloadItem::GetURLChain() const {
   if (!CheckAlive())
-    return v8::Local<v8::Value>();
+    return {};
   return gin::ConvertToV8(isolate_, download_item_->GetUrlChain());
 }
 

shell/browser/api/electron_api_notification.cc

@@ -81,7 +81,7 @@ gin::Handle<Notification> Notification::New(gin_helper::ErrorThrower thrower,
                                             gin::Arguments* args) {
   if (!Browser::Get()->is_ready()) {
     thrower.ThrowError("Cannot create Notification before app is ready");
-    return gin::Handle<Notification>();
+    return {};
   }
   return gin::CreateHandle(thrower.isolate(), new Notification(args));
 }

shell/browser/api/electron_api_protocol.cc

@@ -301,7 +301,7 @@ gin::Handle<Protocol> Protocol::Create(
 // static
 gin::Handle<Protocol> Protocol::New(gin_helper::ErrorThrower thrower) {
   thrower.ThrowError("Protocol cannot be created from JS");
-  return gin::Handle<Protocol>();
+  return {};
 }
 
 // static

shell/browser/api/electron_api_service_worker_context.cc

@@ -132,7 +132,7 @@ v8::Local<v8::Value> ServiceWorkerContext::GetWorkerInfoFromID(
   auto iter = info_map.find(version_id);
   if (iter == info_map.end()) {
     thrower.ThrowError("Could not find service worker with that version_id");
-    return v8::Local<v8::Value>();
+    return {};
   }
   return ServiceWorkerRunningInfoToDict(thrower.isolate(),
                                         std::move(iter->second));

shell/browser/api/electron_api_session.cc

@@ -1583,7 +1583,7 @@ std::optional<gin::Handle<Session>> Session::FromPath(
 gin::Handle<Session> Session::New() {
   gin_helper::ErrorThrower(JavascriptEnvironment::GetIsolate())
       .ThrowError("Session objects cannot be created with 'new'");
-  return gin::Handle<Session>();
+  return {};
 }
 
 void Session::FillObjectTemplate(v8::Isolate* isolate,

shell/browser/api/electron_api_system_preferences_win.cc

@@ -154,7 +154,7 @@ std::string SystemPreferences::GetMediaAccessStatus(
         DeviceAccessStatus::DeviceAccessStatus_Allowed);
   } else {
     thrower.ThrowError("Invalid media type");
-    return std::string();
+    return {};
   }
 }
 

shell/browser/api/electron_api_utility_process.cc

@@ -415,7 +415,7 @@ gin::Handle<UtilityProcessWrapper> UtilityProcessWrapper::Create(
   gin_helper::Dictionary dict;
   if (!args->GetNext(&dict)) {
     args->ThrowTypeError("Options must be an object.");
-    return gin::Handle<UtilityProcessWrapper>();
+    return {};
   }
 
   std::u16string display_name;
@@ -429,19 +429,19 @@ gin::Handle<UtilityProcessWrapper> UtilityProcessWrapper::Create(
   dict.Get("modulePath", &params->script);
   if (dict.Has("args") && !dict.Get("args", &params->args)) {
     args->ThrowTypeError("Invalid value for args");
-    return gin::Handle<UtilityProcessWrapper>();
+    return {};
   }
 
   gin_helper::Dictionary opts;
   if (dict.Get("options", &opts)) {
     if (opts.Has("env") && !opts.Get("env", &env_map)) {
       args->ThrowTypeError("Invalid value for env");
-      return gin::Handle<UtilityProcessWrapper>();
+      return {};
     }
 
     if (opts.Has("execArgv") && !opts.Get("execArgv", &params->exec_args)) {
       args->ThrowTypeError("Invalid value for execArgv");
-      return gin::Handle<UtilityProcessWrapper>();
+      return {};
     }
 
     opts.Get("serviceName", &display_name);

shell/browser/api/electron_api_view.cc

@@ -429,7 +429,7 @@ gin::Handle<View> View::Create(v8::Isolate* isolate) {
     if (gin::ConvertFromV8(isolate, obj, &view))
       return view;
   }
-  return gin::Handle<View>();
+  return {};
 }
 
 // static

shell/browser/api/electron_api_web_contents.cc

@@ -1984,7 +1984,7 @@ gin::Handle<gin_helper::internal::Event> WebContents::MakeEventWithSender(
       ReplyChannel::Create(isolate, std::move(callback))
           ->SendError("WebContents was destroyed");
     }
-    return gin::Handle<gin_helper::internal::Event>();
+    return {};
   }
   gin::Handle<gin_helper::internal::Event> event =
       gin_helper::internal::Event::New(isolate);
@@ -2542,7 +2542,7 @@ std::vector<content::NavigationEntry*> WebContents::GetHistory() const {
   // If the history is empty, it contains only one entry and that is
   // "InitialEntry"
   if (history_length == 1 && controller.GetEntryAtIndex(0)->IsInitialEntry())
-    return std::vector<content::NavigationEntry*>();
+    return {};
 
   std::vector<content::NavigationEntry*> history;
   history.reserve(history_length);

shell/browser/api/electron_api_web_contents_view.cc

@@ -66,7 +66,7 @@ gin::Handle<WebContents> WebContentsView::GetWebContents(v8::Isolate* isolate) {
   if (api_web_contents_)
     return gin::CreateHandle(isolate, api_web_contents_.get());
   else
-    return gin::Handle<WebContents>();
+    return {};
 }
 
 void WebContentsView::SetBackgroundColor(std::optional<WrappedSkColor> color) {
@@ -152,7 +152,7 @@ gin::Handle<WebContentsView> WebContentsView::Create(
     if (gin::ConvertFromV8(isolate, web_contents_view_obj, &web_contents_view))
       return web_contents_view;
   }
-  return gin::Handle<WebContentsView>();
+  return {};
 }
 
 // static

shell/browser/api/electron_api_web_frame_main.cc

@@ -435,14 +435,14 @@ void WebFrameMain::DOMContentLoaded() {
 
 // static
 gin::Handle<WebFrameMain> WebFrameMain::New(v8::Isolate* isolate) {
-  return gin::Handle<WebFrameMain>();
+  return {};
 }
 
 // static
 gin::Handle<WebFrameMain> WebFrameMain::From(v8::Isolate* isolate,
                                              content::RenderFrameHost* rfh) {
   if (!rfh)
-    return gin::Handle<WebFrameMain>();
+    return {};
 
   auto* web_frame = FromRenderFrameHost(rfh);
   if (web_frame)

shell/browser/api/electron_api_web_request.cc

@@ -723,11 +723,11 @@ gin::Handle<WebRequest> WebRequest::From(
     v8::Isolate* isolate,
     content::BrowserContext* browser_context) {
   if (!browser_context)
-    return gin::Handle<WebRequest>();
+    return {};
   auto* user_data =
       static_cast<UserData*>(browser_context->GetUserData(kUserDataKey));
   if (!user_data)
-    return gin::Handle<WebRequest>();
+    return {};
   return gin::CreateHandle(isolate, user_data->data.get());
 }
 

shell/browser/api/message_port.cc

@@ -225,7 +225,7 @@ std::vector<blink::MessagePortChannel> MessagePort::DisentanglePorts(
     const std::vector<gin::Handle<MessagePort>>& ports,
     bool* threw_exception) {
   if (ports.empty())
-    return std::vector<blink::MessagePortChannel>();
+    return {};
 
   std::unordered_set<MessagePort*> visited;
 
@@ -244,7 +244,7 @@ std::vector<blink::MessagePortChannel> MessagePort::DisentanglePorts(
       gin_helper::ErrorThrower(isolate).ThrowError(
           "Port at index " + base::NumberToString(i) + " is " + type + ".");
       *threw_exception = true;
-      return std::vector<blink::MessagePortChannel>();
+      return {};
     }
     visited.insert(port);
   }