BulkLeakCheckServiceTest should handle gracefully the case with 0 credentials to check.

Bug: 1049185
Change-Id: I948f68fb5e7487a072617ed07911fd4d4213f6b5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2094302
Commit-Queue: Vasilii Sukhanov <vasilii@chromium.org>
Reviewed-by: Jan Wilken Dörrie <jdoerrie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#748265}

chrome/browser/extensions/api/passwords_private/password_check_delegate_unittest.cc

@@ -773,6 +773,7 @@ TEST_F(PasswordCheckDelegateTest,
 
   // Verify that the event gets fired once the saved passwords provider is
   // initialized.
+  store().AddLogin(MakeSavedPassword(kExampleCom, kUsername1));
   RunUntilIdle();
   EXPECT_EQ(events::PASSWORDS_PRIVATE_ON_PASSWORD_CHECK_STATUS_CHANGED,
             event_router_observer().events().at(kEventName)->histogram_value);

components/password_manager/core/browser/bulk_leak_check_service.cc

@@ -22,6 +22,8 @@ BulkLeakCheckService::~BulkLeakCheckService() = default;
 void BulkLeakCheckService::CheckUsernamePasswordPairs(
     std::vector<password_manager::LeakCheckCredential> credentials) {
   DVLOG(0) << "Bulk password check, start " << credentials.size();
+  if (credentials.empty())
+    return;
   if (bulk_leak_check_) {
     DCHECK_EQ(State::kRunning, state_);
     // The check is already running. Append the credentials to the list.

components/password_manager/core/browser/bulk_leak_check_service_unittest.cc

@@ -100,6 +100,15 @@ TEST_F(BulkLeakCheckServiceTest, OnCreation) {
   EXPECT_EQ(BulkLeakCheckService::State::kIdle, service().state());
 }
 
+TEST_F(BulkLeakCheckServiceTest, StartWithZeroPasswords) {
+  StrictMock<MockObserver> observer;
+  service().AddObserver(&observer);
+
+  service().CheckUsernamePasswordPairs({});
+  EXPECT_EQ(BulkLeakCheckService::State::kIdle, service().state());
+  EXPECT_EQ(0u, service().GetPendingChecksCount());
+}
+
 TEST_F(BulkLeakCheckServiceTest, Running) {
   StrictMock<MockObserver> observer;
   service().AddObserver(&observer);

components/password_manager/core/browser/ui/bulk_leak_check_service_adapter_unittest.cc

@@ -183,6 +183,9 @@ TEST_F(BulkLeakCheckServiceAdapterTest, StartBulkLeakCheckDedupes) {
 // Checks that trying to start a leak check when another check is already
 // running does nothing and returns false to the caller.
 TEST_F(BulkLeakCheckServiceAdapterTest, MultipleStarts) {
+  store().AddLogin(MakeSavedPassword(kExampleCom, "alice", kPassword1));
+  RunUntilIdle();
+
   auto leak_check = std::make_unique<NiceMockBulkLeakCheck>();
   auto& leak_check_ref = *leak_check;
   EXPECT_CALL(leak_check_ref, CheckCredentials);
@@ -197,6 +200,9 @@ TEST_F(BulkLeakCheckServiceAdapterTest, MultipleStarts) {
 // Checks that stopping the leak check correctly resets the state of the bulk
 // leak check.
 TEST_F(BulkLeakCheckServiceAdapterTest, StopBulkLeakCheck) {
+  store().AddLogin(MakeSavedPassword(kExampleCom, "alice", kPassword1));
+  RunUntilIdle();
+
   auto leak_check = std::make_unique<NiceMockBulkLeakCheck>();
   EXPECT_CALL(*leak_check, CheckCredentials);
   EXPECT_CALL(factory(), TryCreateBulkLeakCheck)