chore: remove background pages implementation (#1861)

Author: yury-s

playwright/src/main/java/com/microsoft/playwright/impl/BrowserContextImpl.java

@@ -46,7 +46,6 @@ class BrowserContextImpl extends ChannelOwner implements BrowserContext {
   private final APIRequestContextImpl request;
   private final ClockImpl clock;
   final List<PageImpl> pages = new ArrayList<>();
-  final List<PageImpl> backgroundPages = new ArrayList<>();
 
   final Router routes = new Router();
   final WebSocketRouter webSocketRoutes = new WebSocketRouter();
@@ -81,7 +80,6 @@ static class HarRecorder {
   }
 
   enum EventType {
-    BACKGROUNDPAGE,
     CLOSE,
     CONSOLE,
     DIALOG,
@@ -133,12 +131,10 @@ String effectiveCloseReason() {
 
   @Override
   public void onBackgroundPage(Consumer<Page> handler) {
-    listeners.add(EventType.BACKGROUNDPAGE, handler);
   }
 
   @Override
   public void offBackgroundPage(Consumer<Page> handler) {
-    listeners.remove(EventType.BACKGROUNDPAGE, handler);
   }
 
   @Override
@@ -340,7 +336,7 @@ public void addInitScript(Path path) {
 
   @Override
   public List<Page> backgroundPages() {
-    return new ArrayList<>(backgroundPages);
+    return Collections.emptyList();
   }
 
   @Override
@@ -719,10 +715,6 @@ protected void handleEvent(String event, JsonObject params) {
       if (page.opener() != null && !page.opener().isClosed()) {
         page.opener().notifyPopup(page);
       }
-    } else if ("backgroundPage".equals(event)) {
-      PageImpl page = connection.getExistingObject(params.getAsJsonObject("page").get("guid").getAsString());
-      backgroundPages.add(page);
-      listeners.notify(EventType.BACKGROUNDPAGE, page);
     } else if ("bindingCall".equals(event)) {
       BindingCall bindingCall = connection.getExistingObject(params.getAsJsonObject("binding").get("guid").getAsString());
       BindingCallback binding = bindings.get(bindingCall.name());

playwright/src/main/java/com/microsoft/playwright/impl/PageImpl.java

@@ -237,7 +237,6 @@ void notifyPopup(PageImpl popup) {
   void didClose() {
     isClosed = true;
     browserContext.pages.remove(this);
-    browserContext.backgroundPages.remove(this);
     listeners.notify(EventType.CLOSE, this);
   }