[Sync] Add ability to save/restore Nigori to SyncEncryptionHandlerImpl

sync/internal_api/sync_encryption_handler_impl_unittest.cc

Index: sync/internal_api/sync_encryption_handler_impl_unittest.cc
diff --git a/sync/internal_api/sync_encryption_handler_impl_unittest.cc b/sync/internal_api/sync_encryption_handler_impl_unittest.cc
index 829ecd2cb9b4d5e775b53e446cce3035b0f1d3f7..afe31a9ae2abcb249d93a5d5d59faf288b9a4f33 100644
--- a/sync/internal_api/sync_encryption_handler_impl_unittest.cc
+++ b/sync/internal_api/sync_encryption_handler_impl_unittest.cc
@@ -59,6 +59,8 @@ class SyncEncryptionHandlerObserverMock
   MOCK_METHOD1(OnCryptographerStateChanged, void(Cryptographer*));  // NOLINT
   MOCK_METHOD2(OnPassphraseTypeChanged, void(PassphraseType,
                                              base::Time));  // NOLINT
+  MOCK_METHOD1(OnLocalSetCustomPassphrase,
+               void(const SyncEncryptionHandler::NigoriState&));  // NOLINT
 };
 
 google::protobuf::RepeatedPtrField<google::protobuf::string>
@@ -1552,8 +1554,13 @@ TEST_F(SyncEncryptionHandlerImplTest, SetCustomPassAfterMigration) {
               OnCryptographerStateChanged(_)).Times(AnyNumber());
   EXPECT_CALL(*observer(),
               OnPassphraseTypeChanged(CUSTOM_PASSPHRASE, _));
+  SyncEncryptionHandler::NigoriState captured_nigori_state;
+  EXPECT_CALL(*observer(), OnLocalSetCustomPassphrase(_))
+      .WillOnce(testing::SaveArg<0>(&captured_nigori_state));
+  std::string captured_bootstrap_token;
   EXPECT_CALL(*observer(),
-              OnBootstrapTokenUpdated(_, PASSPHRASE_BOOTSTRAP_TOKEN));
+              OnBootstrapTokenUpdated(_, PASSPHRASE_BOOTSTRAP_TOKEN))
+      .WillOnce(testing::SaveArg<0>(&captured_bootstrap_token));
   EXPECT_CALL(*observer(),
               OnPassphraseAccepted());
   EXPECT_CALL(*observer(),
@@ -1561,6 +1568,9 @@ TEST_F(SyncEncryptionHandlerImplTest, SetCustomPassAfterMigration) {
   EXPECT_CALL(*observer(),
               OnEncryptionComplete()).Times(2);
   encryption_handler()->SetEncryptionPassphrase(kNewKey, true);
+  Mock::VerifyAndClearExpectations(observer());
+
+  EXPECT_FALSE(captured_bootstrap_token.empty());
   EXPECT_TRUE(encryption_handler()->MigratedToKeystore());
   EXPECT_TRUE(GetCryptographer()->is_ready());
   EXPECT_EQ(encryption_handler()->GetPassphraseType(), CUSTOM_PASSPHRASE);
@@ -1588,6 +1598,22 @@ TEST_F(SyncEncryptionHandlerImplTest, SetCustomPassAfterMigration) {
   sync_pb::EncryptedData new_encrypted;
   new_cryptographer.EncryptString("string", &new_encrypted);
   EXPECT_TRUE(GetCryptographer()->CanDecryptUsingDefaultKey(new_encrypted));
+
+  // Now verify that we can restore the current state using the captured

[maniscalco, 2015/06/10 22:01:45]

I'm interested in your opinion on how to test this.  Currently, we have two test
cases that enable passphrase encryption.  This case and the one below
SetCustomPassAfterMigrationNoKeystoreKey, which I haven't updated, but probably
should.

I chose to test the new save/restore logic as a follow-on step of the existing
test case because it seems that will most closely match how it will be called. 
LMK if you think I should instead break it out into its own case.

[Nicolas Zea, 2015/06/11 17:43:07]

I'm okay with this. One question I have though is what is the expected behavior
for a migration to custom passphrase/frozen implicit passphrase? It might be
good to test that as well.

[maniscalco, 2015/06/15 16:49:18]

I've moved the verification to a new helper method (
VerifyRestoreAfterCustomPassphrase) and now call that method from this case and
SetCustomPassAfterMigrationNoKeystoreKey.

(after offline discussion) Agreed that migration to custom passphrase / frozen
implicit passphrase should invoke the save/restore functionality.  

OK, I've updated SEHI to notify in AttemptToMigrateNigoriToKeystore because it
will cover both the custom and implicit frozen cases.  I've also updated the
migration related tests that end up in these two states.

+  // bootstrap token and nigori state.
+  TearDown();
+  test_user_share_.SetUp();
+  encryption_handler_.reset(new SyncEncryptionHandlerImpl(
+      user_share(), &encryptor_, captured_bootstrap_token, std::string()));
+  encryption_handler_->AddObserver(&observer_);
+  EXPECT_CALL(*observer(), OnCryptographerStateChanged(_)).Times(AnyNumber());
+  EXPECT_CALL(*observer(), OnEncryptedTypesChanged(_, true)).Times(AnyNumber());
+  EXPECT_CALL(*observer(), OnPassphraseTypeChanged(CUSTOM_PASSPHRASE, _));
+  EXPECT_CALL(*observer(), OnEncryptionComplete());
+  encryption_handler_->RestoreNigori(captured_nigori_state);
+  encryption_handler()->Init();
+  Mock::VerifyAndClearExpectations(observer());
+  VerifyMigratedNigoriWithTimestamp(1, CUSTOM_PASSPHRASE, kNewKey);
 }
 
 // Test that if a client without a keystore key (e.g. one without keystore
@@ -1660,6 +1686,8 @@ TEST_F(SyncEncryptionHandlerImplTest,
   EXPECT_CALL(*observer(),
               OnPassphraseTypeChanged(CUSTOM_PASSPHRASE, _));
   EXPECT_CALL(*observer(),
+              OnLocalSetCustomPassphrase(_));
+  EXPECT_CALL(*observer(),
               OnBootstrapTokenUpdated(_, PASSPHRASE_BOOTSTRAP_TOKEN));
   EXPECT_CALL(*observer(),
               OnPassphraseAccepted());