fix: do not report errored pages after context closure (#4346)

Consider the following sequence:
- page opens a popup;
- popup target is attached, we start initializing it;
- user calls browser.close();
- browser is closed, and popup initialization fails;
- we report "errored page" on the already closed context;
- RPC client cannot make sense of this:
  "Cannot find parent object BrowserContext@guid to create Frame@guid"

This issue was revealed during Firefox pipe migration.

src/server/browserContext.ts

@@ -267,6 +267,10 @@ export abstract class BrowserContext extends EventEmitter {
     await this._doUpdateRequestInterception();
   }
 
+  isClosingOrClosed() {
+    return this._closedStatus !== 'open';
+  }
+
   async close() {
     if (this._closedStatus === 'open') {
       this._closedStatus = 'closing';

src/server/chromium/crBrowser.ts

@@ -164,8 +164,13 @@ export class CRBrowser extends Browser {
       this._crPages.set(targetInfo.targetId, crPage);
       crPage.pageOrError().then(pageOrError => {
         const page = crPage._page;
-        if (pageOrError instanceof Error)
+        if (pageOrError instanceof Error) {
+          // Initialization error could have happened because of
+          // context/browser closure. Just ignore the page.
+          if (context!.isClosingOrClosed())
+            return;
           page._setIsError();
+        }
         context!.emit(BrowserContext.Events.Page, page);
         if (opener) {
           opener.pageOrError().then(openerPage => {

src/server/firefox/ffBrowser.ts

@@ -108,8 +108,13 @@ export class FFBrowser extends Browser {
 
     ffPage.pageOrError().then(async pageOrError => {
       const page = ffPage._page;
-      if (pageOrError instanceof Error)
+      if (pageOrError instanceof Error) {
+        // Initialization error could have happened because of
+        // context/browser closure. Just ignore the page.
+        if (context.isClosingOrClosed())
+          return;
         page._setIsError();
+      }
       context.emit(BrowserContext.Events.Page, page);
       if (!opener)
         return;

src/server/webkit/wkBrowser.ts

@@ -156,8 +156,13 @@ export class WKBrowser extends Browser {
 
     wkPage.pageOrError().then(async pageOrError => {
       const page = wkPage._page;
-      if (pageOrError instanceof Error)
+      if (pageOrError instanceof Error) {
+        // Initialization error could have happened because of
+        // context/browser closure. Just ignore the page.
+        if (context!.isClosingOrClosed())
+          return;
         page._setIsError();
+      }
       context!.emit(BrowserContext.Events.Page, page);
       if (!opener)
         return;