fix(router): handle scrollRestoration error in restricted environments (#62186)

In this commit, setting `window.history.scrollRestoration` is wrapped in a try-catch block to prevent `SecurityError` exceptions in restricted contexts such as:

- sandboxed iframes
- partially navigated or inactive windows
- test runners, extensions, or content previews

If an error occurs, a runtime warning with error code [2400] is logged to the console. This avoids breaking app initialization and improves cross-browser safety.

Unfortunately, it's not possible to perform any end-to-end testing of this fix.

PR Close #62186

goldens/public-api/common/errors.api.md

@@ -53,6 +53,8 @@ export const enum RuntimeErrorCode {
     // (undocumented)
     REQUIRED_INPUT_MISSING = 2954,
     // (undocumented)
+    SCROLL_RESTORATION_UNSUPPORTED = 2400,
+    // (undocumented)
     SUSPICIOUS_DATE_FORMAT = 2300,
     // (undocumented)
     TOO_MANY_PRELOADED_IMAGES = 2961,

packages/common/src/errors.ts

@@ -38,6 +38,9 @@ export const enum RuntimeErrorCode {
   NO_PLURAL_MESSAGE_FOUND = 2308,
   VALUE_NOT_A_NUMBER = 2309,
 
+  // Miscellaneous errors
+  SCROLL_RESTORATION_UNSUPPORTED = 2400,
+
   // Keep 2800 - 2900 for Http Errors.
 
   // Image directive errors

packages/common/src/viewport_scroller.ts

@@ -6,7 +6,13 @@
  * found in the LICENSE file at https://angular.dev/license
  */
 
-import {inject, ɵɵdefineInjectable, DOCUMENT} from '@angular/core';
+import {
+  inject,
+  ɵɵdefineInjectable,
+  DOCUMENT,
+  ɵformatRuntimeError as formatRuntimeError,
+} from '@angular/core';
+import {RuntimeErrorCode} from './errors';
 
 /**
  * Defines a scroll position manager. Implemented by `BrowserViewportScroller`.
@@ -131,7 +137,22 @@ export class BrowserViewportScroller implements ViewportScroller {
    * Disables automatic scroll restoration provided by the browser.
    */
   setHistoryScrollRestoration(scrollRestoration: 'auto' | 'manual'): void {
-    this.window.history.scrollRestoration = scrollRestoration;
+    try {
+      this.window.history.scrollRestoration = scrollRestoration;
+    } catch {
+      console.warn(
+        formatRuntimeError(
+          RuntimeErrorCode.SCROLL_RESTORATION_UNSUPPORTED,
+          ngDevMode &&
+            'Failed to set `window.history.scrollRestoration`. ' +
+              'This may occur when:\n' +
+              '• The script is running inside a sandboxed iframe\n' +
+              '• The window is partially navigated or inactive\n' +
+              '• The script is executed in an untrusted or special context (e.g., test runners, browser extensions, or content previews)\n' +
+              'Scroll position may not be preserved across navigation.',
+        ),
+      );
+    }
   }
 
   /**