[Contacts] Check whether context is valid before sharing contacts.

Bug: 985695
Change-Id: Ie6dfa5717219e06a5b7188e50c88b25b32ef69e4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1726049
Commit-Queue: Rayan Kanso <rayankans@chromium.org>
Auto-Submit: Rayan Kanso <rayankans@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Cr-Commit-Position: refs/heads/master@{#682283}

third_party/blink/renderer/modules/contacts_picker/contacts_manager.cc

@@ -135,6 +135,13 @@ void ContactsManager::OnContactsSelected(
     ScriptPromiseResolver* resolver,
     base::Optional<Vector<mojom::blink::ContactInfoPtr>> contacts) {
   ScriptState* script_state = resolver->GetScriptState();
+
+  if (!script_state->ContextIsValid()) {
+    // This can happen if the page is programmatically redirected while
+    // contacts are still being chosen.
+    return;
+  }
+
   ScriptState::Scope scope(script_state);
 
   contact_picker_in_use_ = false;