Safety check: fixed the password check observer to handle multiple callbacks with the same state

Bug: 1015841
Change-Id: I06627da332ec630cdb5fc6f83544613ea9df7ee8
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2115477
Auto-Submit: Andrey Zaytsev <andzaytsev@google.com>
Commit-Queue: Esmael Elmoslimany <aee@chromium.org>
Reviewed-by: Esmael Elmoslimany <aee@chromium.org>
Cr-Commit-Position: refs/heads/master@{#752538}

chrome/browser/ui/webui/settings/safety_check_handler.cc

@@ -512,8 +512,9 @@ void SafetyCheckHandler::OnStateChanged(
       break;
   }
 
-  // Stop observing the leak service in all terminal states.
-  observed_leak_check_.Remove(leak_service_);
+  // Stop observing the leak service in all terminal states, if it's still being
+  // observed.
+  observed_leak_check_.RemoveAll();
 }
 
 void SafetyCheckHandler::OnCredentialDone(

chrome/browser/ui/webui/settings/safety_check_handler_unittest.cc

@@ -575,6 +575,25 @@ TEST_F(SafetyCheckHandlerTest, CheckPasswords_StartedTwice) {
                       "internet connection.");
 }
 
+TEST_F(SafetyCheckHandlerTest, CheckPasswords_ObserverNotifiedTwice) {
+  safety_check_->PerformSafetyCheck();
+  EXPECT_TRUE(test_passwords_delegate_.StartPasswordCheckTriggered());
+  static_cast<password_manager::BulkLeakCheckService::Observer*>(
+      safety_check_.get())
+      ->OnStateChanged(
+          password_manager::BulkLeakCheckService::State::kServiceError);
+  // Another notification about the same state change.
+  static_cast<password_manager::BulkLeakCheckService::Observer*>(
+      safety_check_.get())
+      ->OnStateChanged(
+          password_manager::BulkLeakCheckService::State::kServiceError);
+  const base::DictionaryValue* event =
+      GetSafetyCheckStatusChangedWithDataIfExists(
+          kPasswords,
+          static_cast<int>(SafetyCheckHandler::PasswordsStatus::kError));
+  ASSERT_TRUE(event);
+}
+
 TEST_F(SafetyCheckHandlerTest, CheckPasswords_Safe) {
   safety_check_->PerformSafetyCheck();
   // First, a "running" change of state.