Implementation of sync password hash clearing.

components/password_manager/core/browser/password_store_unittest.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // The passwords in the tests below are all empty because PasswordStoreDefault
 // does not store the actual passwords on OS X (they are stored in the Keychain
 // instead). We could special-case it, but it is easier to just have empty
 // passwords. This will not be needed anymore if crbug.com/466638 is fixed.
 
 #include <stddef.h>
@@ skipping 953 matching lines @@
                       &mock_consumer);
     base::RunLoop().RunUntilIdle();
   }
 
   store->ShutdownOnUIThread();
   base::RunLoop().RunUntilIdle();
 #if defined(OS_MACOSX)
   OSCryptMocker::TearDown();
 #endif
 }
+
+TEST_F(PasswordStoreTest, SavingClearingSyncPassword) {
+#if defined(OS_MACOSX)
+  // Mock Keychain. There is a call to Keychain on initializling
+  // PasswordReuseDetector, so it should be mocked.
+  OSCryptMocker::SetUpWithSingleton();

[vasilii, 2017/06/02 09:30:58]

Why don't you put it into the test setup instead of copy/pasting everywhere?
I think all the tests in the file need it.

[dvadym, 2017/06/02 09:53:14]

Thanks, it makes perfect sense. Done

+#endif
+  scoped_refptr<PasswordStoreDefault> store(new PasswordStoreDefault(
+      base::ThreadTaskRunnerHandle::Get(), base::ThreadTaskRunnerHandle::Get(),
+      base::MakeUnique<LoginDatabase>(test_login_db_file_path())));
+  store->Init(syncer::SyncableService::StartSyncFlare(), nullptr);
+
+  const base::string16 sync_password = base::ASCIIToUTF16("password");
+  const base::string16 input = base::ASCIIToUTF16("123password");
+  store->SaveSyncPasswordHash(sync_password);
+  base::RunLoop().RunUntilIdle();
+
+  // Check that sync password reuse is found.
+  MockPasswordReuseDetectorConsumer mock_consumer;
+  EXPECT_CALL(mock_consumer,
+              OnReuseFound(sync_password, "accounts.google.com", 1, 0));

[vasilii, 2017/06/02 09:30:58]

How can the consumer get the plain-text sync password if we store internally
only hash?
Is it just a substring of |input|?

[dvadym, 2017/06/02 09:53:14]

Yes, it's substring of input, which hash is equal to the sync password hash.

+  store->CheckReuse(input, "https://facebook.com", &mock_consumer);
+  base::RunLoop().RunUntilIdle();
+  testing::Mock::VerifyAndClearExpectations(&mock_consumer);
+
+  // Check that no sync password reuse is found after clearing the saved sync
+  // password hash.
+  store->ClearSyncPasswordHash();
+  EXPECT_CALL(mock_consumer, OnReuseFound(_, _, _, _)).Times(0);
+  store->CheckReuse(input, "https://facebook.com", &mock_consumer);
+  base::RunLoop().RunUntilIdle();
+
+  store->ShutdownOnUIThread();
+  base::RunLoop().RunUntilIdle();
+#if defined(OS_MACOSX)
+  OSCryptMocker::TearDown();
+#endif
+}
 #endif
 
 }  // namespace password_manager