Revert of sync: Add non-blocking type encryption support (https://codereview.chromium.org/423193002/)

Reason for revert:
Both LSAN and Valgrind complains about leaks in the tests.

Original issue's description:
> sync: Add non-blocking type encryption support
> 
> Introduces the framework for dealing with sync encryption in
> non-blocking types.  Unlike directory sync types, non-blocking type
> encryption only encrypts data before it is sent to the server.
> Encrypting the data on-disk is a separate problem.
> 
> Adds code to the ModelTypeSyncWorker so it can access the directory's
> cryptographer (through a CryptographerProvider interface) and use it to
> encrypt entities before it sends them to the server.  If the
> cryptographer is unable to encrypt with the desired key, the worker will
> not commit until the cryptographer returns to a good state.
> 
> Adds the concept of a "desired encryption key" to the data type state.
> When the cryptographer key to be used to encrypt a type changes, this
> will be reflected in the data type state.  The ModelTypeSyncProxy is
> responsible for ensuring that all items which have not yet been
> encrypted with this desired key are enqueued for commit.
> 
> Makes the ModelTypeSyncWorker, EntityTracker, and ModelTypeSyncProxy
> collaborate on the management of undecryptable (inapplicable) updates.
> The EntityTracker keeps track of their version numbers and content, and
> prevents the committing of new items to the server until the
> inapplicable update has been dealt with.  The ModelTypeSyncProxy is
> responsible for saving inapplicable updates across restarts.
> 
> This CL alone is not enough to enable encryption support for
> non-blocking types.  It requires additional code to hook up the
> ModelTypeSyncWorkers to receive cryptographer events.  This will be
> added in a future commit.  In the meantime, this CL includes plenty
> of unit tests to verify the functionality that's being added.
> 
> BUG=351005
> 
> Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=287428

TBR=zea@chromium.org,stanisc@chromium.org,rlarocque@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=351005

Review URL: https://codereview.chromium.org/442623002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@287433 0039d316-1c4b-4281-b951-d872f2087c98

31 files changed, 87 insertions, 1243 deletions

diff --git a/sync/engine/entity_tracker.cc b/sync/engine/entity_tracker.cc
index bad76f9..0f10906 100644
--- a/sync/engine/entity_tracker.cc
+++ b/sync/engine/entity_tracker.cc
@@ -193,14 +193,8 @@ void EntityTracker::ReceiveCommitResponse(const std::string& response_id,
 }
 
 void EntityTracker::ReceiveUpdate(int64 version) {
-  if (version <= highest_gu_response_version_)
-    return;
-
-  highest_gu_response_version_ = version;
-
-  // Got an applicable update newer than any pending updates.  It must be safe
-  // to discard the old pending update, if there was one.
-  ClearPendingUpdate();
+  highest_gu_response_version_ =
+      std::max(highest_gu_response_version_, version);
 
   if (IsInConflict()) {
     // Incoming update clobbers the pending commit on the sync thread.
@@ -209,35 +203,10 @@ void EntityTracker::ReceiveUpdate(int64 version) {
   }
 }
 
-bool EntityTracker::ReceivePendingUpdate(const UpdateResponseData& data) {
-  if (data.response_version < highest_gu_response_version_)
-    return false;
-
-  highest_gu_response_version_ = data.response_version;
-  pending_update_.reset(new UpdateResponseData(data));
-  ClearPendingCommit();
-  return true;
-}
-
-bool EntityTracker::HasPendingUpdate() const {
-  return !!pending_update_;
-}
-
-UpdateResponseData EntityTracker::GetPendingUpdate() const {
-  return *pending_update_;
-}
-
-void EntityTracker::ClearPendingUpdate() {
-  pending_update_.reset();
-}
-
 bool EntityTracker::IsInConflict() const {
   if (!is_commit_pending_)
     return false;
 
-  if (HasPendingUpdate())
-    return true;
-
   if (highest_gu_response_version_ <= highest_commit_response_version_) {
     // The most recent server state was created in a commit made by this
     // client.  We're fully up to date, and therefore not in conflict.
diff --git a/sync/engine/entity_tracker.h b/sync/engine/entity_tracker.h
index e969ff9..db2d09b 100644
--- a/sync/engine/entity_tracker.h
+++ b/sync/engine/entity_tracker.h
@@ -8,10 +8,8 @@
 #include <string>
 
 #include "base/basictypes.h"
-#include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "sync/base/sync_export.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
 #include "sync/protocol/sync.pb.h"
 
 namespace syncer {
@@ -83,20 +81,6 @@ class SYNC_EXPORT EntityTracker {
   // Handles receipt of an update from the server.
   void ReceiveUpdate(int64 version);
 
-  // Handles the receipt of an pending update from the server.
-  //
-  // Returns true if the tracker decides this item is worth keeping.  Returns
-  // false if the item is discarded, which could happen if the version number
-  // is out of date.
-  bool ReceivePendingUpdate(const UpdateResponseData& data);
-
-  // Functions to fetch the latest pending update.
-  bool HasPendingUpdate() const;
-  UpdateResponseData GetPendingUpdate() const;
-
-  // Clears the pending update.  Allows us to resume regular commit behavior.
-  void ClearPendingUpdate();
-
  private:
   // Initializes received update state.  Does not initialize state related to
   // pending commits and sets |is_commit_pending_| to false.
@@ -162,11 +146,6 @@ class SYNC_EXPORT EntityTracker {
   bool deleted_;
   sync_pb::EntitySpecifics specifics_;
 
-  // An update for this item which can't be applied right now.  The presence of
-  // an pending update prevents commits.  As of this writing, the only source
-  // of pending updates is updates we can't decrypt right now.
-  scoped_ptr<UpdateResponseData> pending_update_;
-
   DISALLOW_COPY_AND_ASSIGN(EntityTracker);
 };
 
diff --git a/sync/engine/model_type_entity.cc b/sync/engine/model_type_entity.cc
index 2f758a8..5acf5db 100644
--- a/sync/engine/model_type_entity.cc
+++ b/sync/engine/model_type_entity.cc
@@ -24,8 +24,7 @@ scoped_ptr<ModelTypeEntity> ModelTypeEntity::NewLocalItem(
       specifics,
       false,
       now,
-      now,
-      std::string()));
+      now));
 }
 
 scoped_ptr<ModelTypeEntity> ModelTypeEntity::FromServerUpdate(
@@ -36,8 +35,7 @@ scoped_ptr<ModelTypeEntity> ModelTypeEntity::FromServerUpdate(
     const sync_pb::EntitySpecifics& specifics,
     bool deleted,
     base::Time ctime,
-    base::Time mtime,
-    const std::string& encryption_key_name) {
+    base::Time mtime) {
   return scoped_ptr<ModelTypeEntity>(new ModelTypeEntity(0,
                                                          0,
                                                          0,
@@ -49,8 +47,7 @@ scoped_ptr<ModelTypeEntity> ModelTypeEntity::FromServerUpdate(
                                                          specifics,
                                                          deleted,
                                                          ctime,
-                                                         mtime,
-                                                         encryption_key_name));
+                                                         mtime));
 }
 
 ModelTypeEntity::ModelTypeEntity(int64 sequence_number,
@@ -64,8 +61,7 @@ ModelTypeEntity::ModelTypeEntity(int64 sequence_number,
                                  const sync_pb::EntitySpecifics& specifics,
                                  bool deleted,
                                  base::Time ctime,
-                                 base::Time mtime,
-                                 const std::string& encryption_key_name)
+                                 base::Time mtime)
     : sequence_number_(sequence_number),
       commit_requested_sequence_number_(commit_requested_sequence_number),
       acked_sequence_number_(acked_sequence_number),
@@ -77,8 +73,7 @@ ModelTypeEntity::ModelTypeEntity(int64 sequence_number,
       specifics_(specifics),
       deleted_(deleted),
       ctime_(ctime),
-      mtime_(mtime),
-      encryption_key_name_(encryption_key_name) {
+      mtime_(mtime) {
 }
 
 ModelTypeEntity::~ModelTypeEntity() {
@@ -108,8 +103,7 @@ void ModelTypeEntity::ApplyUpdateFromServer(
     int64 update_version,
     bool deleted,
     const sync_pb::EntitySpecifics& specifics,
-    base::Time mtime,
-    const std::string& encryption_key_name) {
+    base::Time mtime) {
   // There was a conflict and the server just won it.
   // This implicitly acks all outstanding commits because a received update
   // will clobber any pending commits on the sync thread.
@@ -127,15 +121,6 @@ void ModelTypeEntity::MakeLocalChange(
   specifics_ = specifics;
 }
 
-void ModelTypeEntity::UpdateDesiredEncryptionKey(const std::string& name) {
-  if (encryption_key_name_ == name)
-    return;
-
-  // Schedule commit with the expectation that the worker will re-encrypt with
-  // the latest encryption key as it does.
-  sequence_number_++;
-}
-
 void ModelTypeEntity::Delete() {
   sequence_number_++;
   specifics_.Clear();
@@ -159,15 +144,12 @@ void ModelTypeEntity::SetCommitRequestInProgress() {
   commit_requested_sequence_number_ = sequence_number_;
 }
 
-void ModelTypeEntity::ReceiveCommitResponse(
-    const std::string& id,
-    int64 sequence_number,
-    int64 response_version,
-    const std::string& encryption_key_name) {
+void ModelTypeEntity::ReceiveCommitResponse(const std::string& id,
+                                            int64 sequence_number,
+                                            int64 response_version) {
   id_ = id;  // The server can assign us a new ID in a commit response.
   acked_sequence_number_ = sequence_number;
   base_version_ = response_version;
-  encryption_key_name_ = encryption_key_name;
 }
 
 void ModelTypeEntity::ClearTransientSyncState() {
diff --git a/sync/engine/model_type_entity.h b/sync/engine/model_type_entity.h
index e05d469..abc67a9 100644
--- a/sync/engine/model_type_entity.h
+++ b/sync/engine/model_type_entity.h
@@ -46,8 +46,7 @@ class SYNC_EXPORT_PRIVATE ModelTypeEntity {
       const sync_pb::EntitySpecifics& specifics,
       bool deleted,
       base::Time ctime,
-      base::Time mtime,
-      const std::string& encryption_key_name);
+      base::Time mtime);
 
   // TODO(rlarocque): Implement FromDisk constructor when we implement storage.
 
@@ -80,17 +79,11 @@ class SYNC_EXPORT_PRIVATE ModelTypeEntity {
   void ApplyUpdateFromServer(int64 update_version,
                              bool deleted,
                              const sync_pb::EntitySpecifics& specifics,
-                             base::Time mtime,
-                             const std::string& encryption_key_name);
+                             base::Time mtime);
 
   // Applies a local change to this item.
   void MakeLocalChange(const sync_pb::EntitySpecifics& specifics);
 
-  // Schedule a commit if the |name| does not match this item's last known
-  // encryption key.  The worker that performs the commit is expected to
-  // encrypt the item using the latest available key.
-  void UpdateDesiredEncryptionKey(const std::string& name);
-
   // Applies a local deletion to this item.
   void Delete();
 
@@ -111,8 +104,7 @@ class SYNC_EXPORT_PRIVATE ModelTypeEntity {
   // reached the server.
   void ReceiveCommitResponse(const std::string& id,
                              int64 sequence_number,
-                             int64 response_version,
-                             const std::string& encryption_key_name);
+                             int64 response_version);
 
   // Clears any in-memory sync state associated with outstanding commits.
   void ClearTransientSyncState();
@@ -132,8 +124,7 @@ class SYNC_EXPORT_PRIVATE ModelTypeEntity {
                   const sync_pb::EntitySpecifics& specifics,
                   bool deleted,
                   base::Time ctime,
-                  base::Time mtime,
-                  const std::string& encryption_key_name);
+                  base::Time mtime);
 
   // A sequence number used to track in-progress commits.  Each local change
   // increments this number.
@@ -194,10 +185,6 @@ class SYNC_EXPORT_PRIVATE ModelTypeEntity {
   // doesn't bother to inspect their values.
   base::Time ctime_;
   base::Time mtime_;
-
-  // The name of the encryption key used to encrypt this item on the server.
-  // Empty when no encryption is in use.
-  std::string encryption_key_name_;
 };
 
 }  // namespace syncer
diff --git a/sync/engine/model_type_entity_unittest.cc b/sync/engine/model_type_entity_unittest.cc
index 817bc84..c605732 100644
--- a/sync/engine/model_type_entity_unittest.cc
+++ b/sync/engine/model_type_entity_unittest.cc
@@ -64,8 +64,7 @@ TEST_F(ModelTypeEntityTest, FromServerUpdate) {
                                         specifics,
                                         false,
                                         kCtime,
-                                        kMtime,
-                                        std::string()));
+                                        kMtime));
 
   EXPECT_TRUE(entity->IsWriteRequired());
   EXPECT_FALSE(entity->IsUnsynced());
@@ -88,8 +87,7 @@ TEST_F(ModelTypeEntityTest, TombstoneUpdate) {
                                         sync_pb::EntitySpecifics(),
                                         true,
                                         kCtime,
-                                        kMtime,
-                                        std::string()));
+                                        kMtime));
 
   EXPECT_TRUE(entity->IsWriteRequired());
   EXPECT_FALSE(entity->IsUnsynced());
@@ -109,15 +107,13 @@ TEST_F(ModelTypeEntityTest, ApplyUpdate) {
                                         specifics,
                                         false,
                                         kCtime,
-                                        kMtime,
-                                        std::string()));
+                                        kMtime));
 
   // A deletion update one version later.
   entity->ApplyUpdateFromServer(11,
                                 true,
                                 sync_pb::EntitySpecifics(),
-                                kMtime + base::TimeDelta::FromSeconds(10),
-                                std::string());
+                                kMtime + base::TimeDelta::FromSeconds(10));
 
   EXPECT_TRUE(entity->IsWriteRequired());
   EXPECT_FALSE(entity->IsUnsynced());
@@ -134,8 +130,7 @@ TEST_F(ModelTypeEntityTest, LocalChange) {
                                         specifics,
                                         false,
                                         kCtime,
-                                        kMtime,
-                                        std::string()));
+                                        kMtime));
 
   sync_pb::EntitySpecifics specifics2;
   specifics2.CopyFrom(specifics);
@@ -161,8 +156,7 @@ TEST_F(ModelTypeEntityTest, LocalDeletion) {
                                         specifics,
                                         false,
                                         kCtime,
-                                        kMtime,
-                                        std::string()));
+                                        kMtime));
 
   entity->Delete();
 
diff --git a/sync/engine/model_type_sync_proxy.h b/sync/engine/model_type_sync_proxy.h
index 3c6e079..706fbc7 100644
--- a/sync/engine/model_type_sync_proxy.h
+++ b/sync/engine/model_type_sync_proxy.h
@@ -21,8 +21,7 @@ class SYNC_EXPORT_PRIVATE ModelTypeSyncProxy {
       const CommitResponseDataList& response_list) = 0;
   virtual void OnUpdateReceived(
       const DataTypeState& type_state,
-      const UpdateResponseDataList& response_list,
-      const UpdateResponseDataList& pending_updates) = 0;
+      const UpdateResponseDataList& response_list) = 0;
 };
 
 }  // namespace syncer
diff --git a/sync/engine/model_type_sync_proxy_impl.cc b/sync/engine/model_type_sync_proxy_impl.cc
index 7ea5d52..7b2148a 100644
--- a/sync/engine/model_type_sync_proxy_impl.cc
+++ b/sync/engine/model_type_sync_proxy_impl.cc
@@ -18,7 +18,6 @@ ModelTypeSyncProxyImpl::ModelTypeSyncProxyImpl(ModelType type)
       is_preferred_(false),
       is_connected_(false),
       entities_deleter_(&entities_),
-      pending_updates_map_deleter_(&pending_updates_map_),
       weak_ptr_factory_for_ui_(this),
       weak_ptr_factory_for_sync_(this) {
 }
@@ -52,12 +51,10 @@ void ModelTypeSyncProxyImpl::Enable(
   data_type_state_.progress_marker.set_data_type_id(
       GetSpecificsFieldNumberFromModelType(type_));
 
-  UpdateResponseDataList saved_pending_updates = GetPendingUpdates();
   sync_context_proxy_ = sync_context_proxy.Pass();
   sync_context_proxy_->ConnectTypeToSync(
       GetModelType(),
       data_type_state_,
-      saved_pending_updates,
       weak_ptr_factory_for_sync_.GetWeakPtr());
 }
 
@@ -183,18 +180,16 @@ void ModelTypeSyncProxyImpl::OnCommitCompleted(
     } else {
       it->second->ReceiveCommitResponse(response_data.id,
                                         response_data.sequence_number,
-                                        response_data.response_version,
-                                        data_type_state_.encryption_key_name);
+                                        response_data.response_version);
     }
   }
 }
 
 void ModelTypeSyncProxyImpl::OnUpdateReceived(
     const DataTypeState& data_type_state,
-    const UpdateResponseDataList& response_list,
-    const UpdateResponseDataList& pending_updates) {
-  bool got_new_encryption_requirements = data_type_state_.encryption_key_name !=
-                                         data_type_state.encryption_key_name;
+    const UpdateResponseDataList& response_list) {
+  bool initial_sync_just_finished =
+      !data_type_state_.initial_sync_done && data_type_state.initial_sync_done;
 
   data_type_state_ = data_type_state;
 
@@ -204,14 +199,6 @@ void ModelTypeSyncProxyImpl::OnUpdateReceived(
     const UpdateResponseData& response_data = *list_it;
     const std::string& client_tag_hash = response_data.client_tag_hash;
 
-    UpdateMap::iterator old_it = pending_updates_map_.find(client_tag_hash);
-    if (old_it != pending_updates_map_.end()) {
-      // If we're being asked to apply an update to this entity, this overrides
-      // the previous pending updates.
-      delete old_it->second;
-      pending_updates_map_.erase(old_it);
-    }
-
     EntityMap::iterator it = entities_.find(client_tag_hash);
     if (it == entities_.end()) {
       scoped_ptr<ModelTypeEntity> entity =
@@ -222,74 +209,22 @@ void ModelTypeSyncProxyImpl::OnUpdateReceived(
                                             response_data.specifics,
                                             response_data.deleted,
                                             response_data.ctime,
-                                            response_data.mtime,
-                                            response_data.encryption_key_name);
+                                            response_data.mtime);
       entities_.insert(std::make_pair(client_tag_hash, entity.release()));
     } else {
       ModelTypeEntity* entity = it->second;
       entity->ApplyUpdateFromServer(response_data.response_version,
                                     response_data.deleted,
                                     response_data.specifics,
-                                    response_data.mtime,
-                                    response_data.encryption_key_name);
-
+                                    response_data.mtime);
       // TODO: Do something special when conflicts are detected.
     }
-
-    // If the received entity has out of date encryption, we schedule another
-    // commit to fix it.
-    if (data_type_state_.encryption_key_name !=
-        response_data.encryption_key_name) {
-      EntityMap::iterator it2 = entities_.find(client_tag_hash);
-      it2->second->UpdateDesiredEncryptionKey(
-          data_type_state_.encryption_key_name);
-    }
   }
 
-  // Save pending updates in the appropriate data structure.
-  for (UpdateResponseDataList::const_iterator list_it = pending_updates.begin();
-       list_it != pending_updates.end();
-       ++list_it) {
-    const UpdateResponseData& update = *list_it;
-    const std::string& client_tag_hash = update.client_tag_hash;
-
-    UpdateMap::iterator lookup_it = pending_updates_map_.find(client_tag_hash);
-    if (lookup_it == pending_updates_map_.end()) {
-      pending_updates_map_.insert(
-          std::make_pair(client_tag_hash, new UpdateResponseData(update)));
-    } else if (lookup_it->second->response_version <= update.response_version) {
-      delete lookup_it->second;
-      pending_updates_map_.erase(lookup_it);
-      pending_updates_map_.insert(
-          std::make_pair(client_tag_hash, new UpdateResponseData(update)));
-    } else {
-      // Received update is stale, do not overwrite existing.
-    }
-  }
-
-  if (got_new_encryption_requirements) {
-    for (EntityMap::iterator it = entities_.begin(); it != entities_.end();
-         ++it) {
-      it->second->UpdateDesiredEncryptionKey(
-          data_type_state_.encryption_key_name);
-    }
-  }
-
-  // We may have new reasons to commit by the time this function is done.
-  FlushPendingCommitRequests();
+  if (initial_sync_just_finished)
+    FlushPendingCommitRequests();
 
   // TODO: Inform the model of the new or updated data.
-  // TODO: Persist the new data on disk.
-}
-
-UpdateResponseDataList ModelTypeSyncProxyImpl::GetPendingUpdates() {
-  UpdateResponseDataList pending_updates_list;
-  for (UpdateMap::const_iterator it = pending_updates_map_.begin();
-       it != pending_updates_map_.end();
-       ++it) {
-    pending_updates_list.push_back(*it->second);
-  }
-  return pending_updates_list;
 }
 
 void ModelTypeSyncProxyImpl::ClearTransientSyncState() {
@@ -304,7 +239,7 @@ void ModelTypeSyncProxyImpl::ClearSyncState() {
        ++it) {
     it->second->ClearSyncState();
   }
-  STLDeleteValues(&pending_updates_map_);
+
   data_type_state_ = DataTypeState();
 }
 
diff --git a/sync/engine/model_type_sync_proxy_impl.h b/sync/engine/model_type_sync_proxy_impl.h
index f160669..2390eda 100644
--- a/sync/engine/model_type_sync_proxy_impl.h
+++ b/sync/engine/model_type_sync_proxy_impl.h
@@ -73,16 +73,7 @@ class SYNC_EXPORT_PRIVATE ModelTypeSyncProxyImpl : base::NonThreadSafe {
   // Informs this object that there are some incoming updates is should
   // handle.
   void OnUpdateReceived(const DataTypeState& type_state,
-                        const UpdateResponseDataList& response_list,
-                        const UpdateResponseDataList& pending_updates);
-
-  // Returns the list of pending updates.
-  //
-  // This is used as a helper function, but it's public mainly for testing.
-  // The current test harness setup doesn't allow us to test the data that the
-  // proxy sends to the worker during initialization, so we use this to inspect
-  // its state instead.
-  UpdateResponseDataList GetPendingUpdates();
+                        const UpdateResponseDataList& response_list);
 
   // Returns the long-lived WeakPtr that is intended to be registered with the
   // ProfileSyncService.
@@ -90,7 +81,6 @@ class SYNC_EXPORT_PRIVATE ModelTypeSyncProxyImpl : base::NonThreadSafe {
 
  private:
   typedef std::map<std::string, ModelTypeEntity*> EntityMap;
-  typedef std::map<std::string, UpdateResponseData*> UpdateMap;
 
   // Sends all commit requests that are due to be sent to the sync thread.
   void FlushPendingCommitRequests();
@@ -133,12 +123,6 @@ class SYNC_EXPORT_PRIVATE ModelTypeSyncProxyImpl : base::NonThreadSafe {
   EntityMap entities_;
   STLValueDeleter<EntityMap> entities_deleter_;
 
-  // A set of updates that can not be applied at this time.  These are never
-  // used by the model.  They are kept here only so we can save and restore
-  // them across restarts, and keep them in sync with our progress markers.
-  UpdateMap pending_updates_map_;
-  STLValueDeleter<UpdateMap> pending_updates_map_deleter_;
-
   // We use two different WeakPtrFactories because we want the pointers they
   // issue to have different lifetimes.  When asked to disconnect from the sync
   // thread, we want to make sure that no tasks generated as part of the
diff --git a/sync/engine/model_type_sync_proxy_impl_unittest.cc b/sync/engine/model_type_sync_proxy_impl_unittest.cc
index 581d511..0597657 100644
--- a/sync/engine/model_type_sync_proxy_impl_unittest.cc
+++ b/sync/engine/model_type_sync_proxy_impl_unittest.cc
@@ -77,22 +77,6 @@ class ModelTypeSyncProxyImplTest : public ::testing::Test {
                         const std::string& value);
   void TombstoneFromServer(int64 version_offset, const std::string& tag);
 
-  // Emulate the receipt of pending updates from the server.
-  // Pending updates are usually caused by a temporary decryption failure.
-  void PendingUpdateFromServer(int64 version_offset,
-                               const std::string& tag,
-                               const std::string& value,
-                               const std::string& key_name);
-
-  // Returns true if the proxy has an pending update with specified tag.
-  bool HasPendingUpdate(const std::string& tag) const;
-
-  // Returns the pending update with the specified tag.
-  UpdateResponseData GetPendingUpdate(const std::string& tag) const;
-
-  // Returns the number of pending updates.
-  size_t GetNumPendingUpdates() const;
-
   // Read emitted commit requests as batches.
   size_t GetNumCommitRequestLists();
   CommitRequestDataList GetNthCommitRequestList(size_t n);
@@ -104,22 +88,10 @@ class ModelTypeSyncProxyImplTest : public ::testing::Test {
   // Sends the type sync proxy a successful commit response.
   void SuccessfulCommitResponse(const CommitRequestData& request_data);
 
-  // Sends the type sync proxy an updated DataTypeState to let it know that
-  // the desired encryption key has changed.
-  void UpdateDesiredEncryptionKey(const std::string& key_name);
-
-  // Sets the key_name that the mock ModelTypeSyncWorker will claim is in use
-  // when receiving items.
-  void SetServerEncryptionKey(const std::string& key_name);
-
  private:
   static std::string GenerateTagHash(const std::string& tag);
   static sync_pb::EntitySpecifics GenerateSpecifics(const std::string& tag,
                                                     const std::string& value);
-  static sync_pb::EntitySpecifics GenerateEncryptedSpecifics(
-      const std::string& tag,
-      const std::string& value,
-      const std::string& key_name);
 
   int64 GetServerVersion(const std::string& tag);
   void SetServerVersion(const std::string& tag, int64 version);
@@ -169,7 +141,7 @@ void ModelTypeSyncProxyImplTest::Disable() {
 void ModelTypeSyncProxyImplTest::ReEnable() {
   DCHECK(!type_sync_proxy_->IsConnected());
 
-  // Prepare a new MockModelTypeSyncWorker instance, just as we would
+  // Prepare a new NonBlockingTypeProcesorCore instance, just as we would
   // if this happened in the real world.
   mock_worker_ = new MockModelTypeSyncWorker();
   injectable_sync_context_proxy_.reset(
@@ -193,8 +165,7 @@ void ModelTypeSyncProxyImplTest::OnInitialSyncDone() {
   data_type_state_.initial_sync_done = true;
   UpdateResponseDataList empty_update_list;
 
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, empty_update_list, empty_update_list);
+  type_sync_proxy_->OnUpdateReceived(data_type_state_, empty_update_list);
 }
 
 void ModelTypeSyncProxyImplTest::UpdateFromServer(int64 version_offset,
@@ -206,25 +177,7 @@ void ModelTypeSyncProxyImplTest::UpdateFromServer(int64 version_offset,
 
   UpdateResponseDataList list;
   list.push_back(data);
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, list, UpdateResponseDataList());
-}
-
-void ModelTypeSyncProxyImplTest::PendingUpdateFromServer(
-    int64 version_offset,
-    const std::string& tag,
-    const std::string& value,
-    const std::string& key_name) {
-  const std::string tag_hash = GenerateTagHash(tag);
-  UpdateResponseData data = mock_worker_->UpdateFromServer(
-      version_offset,
-      tag_hash,
-      GenerateEncryptedSpecifics(tag, value, key_name));
-
-  UpdateResponseDataList list;
-  list.push_back(data);
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, UpdateResponseDataList(), list);
+  type_sync_proxy_->OnUpdateReceived(data_type_state_, list);
 }
 
 void ModelTypeSyncProxyImplTest::TombstoneFromServer(int64 version_offset,
@@ -237,40 +190,7 @@ void ModelTypeSyncProxyImplTest::TombstoneFromServer(int64 version_offset,
 
   UpdateResponseDataList list;
   list.push_back(data);
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, list, UpdateResponseDataList());
-}
-
-bool ModelTypeSyncProxyImplTest::HasPendingUpdate(
-    const std::string& tag) const {
-  const std::string client_tag_hash = GenerateTagHash(tag);
-  const UpdateResponseDataList list = type_sync_proxy_->GetPendingUpdates();
-  for (UpdateResponseDataList::const_iterator it = list.begin();
-       it != list.end();
-       ++it) {
-    if (it->client_tag_hash == client_tag_hash)
-      return true;
-  }
-  return false;
-}
-
-UpdateResponseData ModelTypeSyncProxyImplTest::GetPendingUpdate(
-    const std::string& tag) const {
-  DCHECK(HasPendingUpdate(tag));
-  const std::string client_tag_hash = GenerateTagHash(tag);
-  const UpdateResponseDataList list = type_sync_proxy_->GetPendingUpdates();
-  for (UpdateResponseDataList::const_iterator it = list.begin();
-       it != list.end();
-       ++it) {
-    if (it->client_tag_hash == client_tag_hash)
-      return *it;
-  }
-  NOTREACHED();
-  return UpdateResponseData();
-}
-
-size_t ModelTypeSyncProxyImplTest::GetNumPendingUpdates() const {
-  return type_sync_proxy_->GetPendingUpdates().size();
+  type_sync_proxy_->OnUpdateReceived(data_type_state_, list);
 }
 
 void ModelTypeSyncProxyImplTest::SuccessfulCommitResponse(
@@ -280,18 +200,6 @@ void ModelTypeSyncProxyImplTest::SuccessfulCommitResponse(
   type_sync_proxy_->OnCommitCompleted(data_type_state_, list);
 }
 
-void ModelTypeSyncProxyImplTest::UpdateDesiredEncryptionKey(
-    const std::string& key_name) {
-  data_type_state_.encryption_key_name = key_name;
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, UpdateResponseDataList(), UpdateResponseDataList());
-}
-
-void ModelTypeSyncProxyImplTest::SetServerEncryptionKey(
-    const std::string& key_name) {
-  mock_worker_->SetServerEncryptionKey(key_name);
-}
-
 std::string ModelTypeSyncProxyImplTest::GenerateTagHash(
     const std::string& tag) {
   return syncable::GenerateSyncableHash(kModelType, tag);
@@ -306,19 +214,6 @@ sync_pb::EntitySpecifics ModelTypeSyncProxyImplTest::GenerateSpecifics(
   return specifics;
 }
 
-// These tests never decrypt anything, so we can get away with faking the
-// encryption for now.
-sync_pb::EntitySpecifics ModelTypeSyncProxyImplTest::GenerateEncryptedSpecifics(
-    const std::string& tag,
-    const std::string& value,
-    const std::string& key_name) {
-  sync_pb::EntitySpecifics specifics;
-  AddDefaultFieldValue(kModelType, &specifics);
-  specifics.mutable_encrypted()->set_key_name(key_name);
-  specifics.mutable_encrypted()->set_blob("BLOB" + key_name);
-  return specifics;
-}
-
 size_t ModelTypeSyncProxyImplTest::GetNumCommitRequestLists() {
   return mock_worker_->GetNumCommitRequestLists();
 }
@@ -565,125 +460,4 @@ TEST_F(ModelTypeSyncProxyImplTest, Disable) {
   EXPECT_TRUE(HasCommitRequestForTag("tag3"));
 }
 
-// Test receipt of pending updates.
-TEST_F(ModelTypeSyncProxyImplTest, ReceivePendingUpdates) {
-  EXPECT_FALSE(HasPendingUpdate("tag1"));
-  EXPECT_EQ(0U, GetNumPendingUpdates());
-
-  // Receive a pending update.
-  PendingUpdateFromServer(5, "tag1", "value1", "key1");
-  EXPECT_EQ(1U, GetNumPendingUpdates());
-  ASSERT_TRUE(HasPendingUpdate("tag1"));
-  UpdateResponseData data1 = GetPendingUpdate("tag1");
-  EXPECT_EQ(5, data1.response_version);
-
-  // Receive an updated version of a pending update.
-  // It should overwrite the existing item.
-  PendingUpdateFromServer(10, "tag1", "value15", "key1");
-  EXPECT_EQ(1U, GetNumPendingUpdates());
-  ASSERT_TRUE(HasPendingUpdate("tag1"));
-  UpdateResponseData data2 = GetPendingUpdate("tag1");
-  EXPECT_EQ(15, data2.response_version);
-
-  // Receive a stale version of a pending update.
-  // It should have no effect.
-  PendingUpdateFromServer(-3, "tag1", "value12", "key1");
-  EXPECT_EQ(1U, GetNumPendingUpdates());
-  ASSERT_TRUE(HasPendingUpdate("tag1"));
-  UpdateResponseData data3 = GetPendingUpdate("tag1");
-  EXPECT_EQ(15, data3.response_version);
-}
-
-// Test that Disable clears pending update state.
-TEST_F(ModelTypeSyncProxyImplTest, DisableWithPendingUpdates) {
-  PendingUpdateFromServer(5, "tag1", "value1", "key1");
-  EXPECT_EQ(1U, GetNumPendingUpdates());
-  ASSERT_TRUE(HasPendingUpdate("tag1"));
-
-  Disable();
-  ReEnable();
-
-  EXPECT_EQ(0U, GetNumPendingUpdates());
-  EXPECT_FALSE(HasPendingUpdate("tag1"));
-}
-
-// Test that Disconnect does not clear pending update state.
-TEST_F(ModelTypeSyncProxyImplTest, DisconnectWithPendingUpdates) {
-  PendingUpdateFromServer(5, "tag1", "value1", "key1");
-  EXPECT_EQ(1U, GetNumPendingUpdates());
-  ASSERT_TRUE(HasPendingUpdate("tag1"));
-
-  Disconnect();
-  ReEnable();
-
-  EXPECT_EQ(1U, GetNumPendingUpdates());
-  EXPECT_TRUE(HasPendingUpdate("tag1"));
-}
-
-// Test re-encrypt everything when desired encryption key changes.
-TEST_F(ModelTypeSyncProxyImplTest, ReEncryptCommitsWithNewKey) {
-  InitializeToReadyState();
-
-  // Commit an item.
-  WriteItem("tag1", "value1");
-  ASSERT_TRUE(HasCommitRequestForTag("tag1"));
-  const CommitRequestData& tag1_v1_data = GetLatestCommitRequestForTag("tag1");
-  SuccessfulCommitResponse(tag1_v1_data);
-
-  // Create another item and don't wait for its commit response.
-  WriteItem("tag2", "value2");
-
-  ASSERT_EQ(2U, GetNumCommitRequestLists());
-
-  // Receive notice that the account's desired encryption key has changed.
-  UpdateDesiredEncryptionKey("k1");
-
-  // That should trigger a new commit request.
-  ASSERT_EQ(3U, GetNumCommitRequestLists());
-  EXPECT_EQ(2U, GetNthCommitRequestList(2).size());
-
-  const CommitRequestData& tag1_enc = GetLatestCommitRequestForTag("tag1");
-  const CommitRequestData& tag2_enc = GetLatestCommitRequestForTag("tag2");
-
-  SuccessfulCommitResponse(tag1_enc);
-  SuccessfulCommitResponse(tag2_enc);
-
-  // And that should be the end of it.
-  ASSERT_EQ(3U, GetNumCommitRequestLists());
-}
-
-// Test receipt of updates with new and old keys.
-TEST_F(ModelTypeSyncProxyImplTest, ReEncryptUpdatesWithNewKey) {
-  InitializeToReadyState();
-
-  // Receive an unencrpted update.
-  UpdateFromServer(5, "no_enc", "value1");
-
-  ASSERT_EQ(0U, GetNumCommitRequestLists());
-
-  // Set desired encryption key to k2 to force updates to some items.
-  UpdateDesiredEncryptionKey("k2");
-
-  ASSERT_EQ(1U, GetNumCommitRequestLists());
-  EXPECT_EQ(1U, GetNthCommitRequestList(0).size());
-  EXPECT_TRUE(HasCommitRequestForTag("no_enc"));
-
-  // Receive an update that was encrypted with key k1.
-  SetServerEncryptionKey("k1");
-  UpdateFromServer(10, "enc_k1", "value1");
-
-  // Receipt of updates encrypted with old key also forces a re-encrypt commit.
-  ASSERT_EQ(2U, GetNumCommitRequestLists());
-  EXPECT_EQ(1U, GetNthCommitRequestList(1).size());
-  EXPECT_TRUE(HasCommitRequestForTag("enc_k1"));
-
-  // Receive an update that was encrypted with key k2.
-  SetServerEncryptionKey("k2");
-  UpdateFromServer(15, "enc_k2", "value1");
-
-  // That was the correct key, so no re-encryption is required.
-  EXPECT_EQ(2U, GetNumCommitRequestLists());
-  EXPECT_FALSE(HasCommitRequestForTag("enc_k2"));
-}
-
 }  // namespace syncer
diff --git a/sync/engine/model_type_sync_worker_impl.cc b/sync/engine/model_type_sync_worker_impl.cc
index a58400f4..a5402c2 100644
--- a/sync/engine/model_type_sync_worker_impl.cc
+++ b/sync/engine/model_type_sync_worker_impl.cc
@@ -13,7 +13,6 @@
 #include "sync/engine/model_type_sync_proxy.h"
 #include "sync/engine/non_blocking_type_commit_contribution.h"
 #include "sync/syncable/syncable_util.h"
-#include "sync/util/cryptographer.h"
 #include "sync/util/time.h"
 
 namespace syncer {
@@ -21,14 +20,11 @@ namespace syncer {
 ModelTypeSyncWorkerImpl::ModelTypeSyncWorkerImpl(
     ModelType type,
     const DataTypeState& initial_state,
-    const UpdateResponseDataList& saved_pending_updates,
-    CryptographerProvider* cryptographer_provider,
     NudgeHandler* nudge_handler,
     scoped_ptr<ModelTypeSyncProxy> type_sync_proxy)
     : type_(type),
       data_type_state_(initial_state),
       type_sync_proxy_(type_sync_proxy.Pass()),
-      cryptographer_provider_(cryptographer_provider),
       nudge_handler_(nudge_handler),
       entities_deleter_(&entities_),
       weak_ptr_factory_(this) {
@@ -36,18 +32,6 @@ ModelTypeSyncWorkerImpl::ModelTypeSyncWorkerImpl(
   if (!data_type_state_.initial_sync_done) {
     nudge_handler_->NudgeForInitialDownload(type_);
   }
-
-  for (UpdateResponseDataList::const_iterator it =
-           saved_pending_updates.begin();
-       it != saved_pending_updates.end();
-       ++it) {
-    EntityTracker* entity_tracker = EntityTracker::FromServerUpdate(
-        it->id, it->client_tag_hash, it->response_version);
-    entity_tracker->ReceivePendingUpdate(*it);
-    entities_.insert(std::make_pair(it->client_tag_hash, entity_tracker));
-  }
-
-  TryDecryptPendingUpdates();
 }
 
 ModelTypeSyncWorkerImpl::~ModelTypeSyncWorkerImpl() {
@@ -58,33 +42,6 @@ ModelType ModelTypeSyncWorkerImpl::GetModelType() const {
   return type_;
 }
 
-bool ModelTypeSyncWorkerImpl::IsEncryptionRequired() const {
-  return !data_type_state_.encryption_key_name.empty();
-}
-
-void ModelTypeSyncWorkerImpl::SetEncryptionKeyName(const std::string& name) {
-  if (data_type_state_.encryption_key_name == name)
-    return;
-
-  data_type_state_.encryption_key_name = name;
-
-  // Pretend to send an update.  This will cause the TypeSyncProxy to notice
-  // the new encryption key and take appropriate action.
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, UpdateResponseDataList(), UpdateResponseDataList());
-}
-
-void ModelTypeSyncWorkerImpl::OnCryptographerStateChanged() {
-  TryDecryptPendingUpdates();
-
-  ScopedCryptographerRef scoped_cryptographer_ref;
-  cryptographer_provider_->InitScopedCryptographerRef(
-      &scoped_cryptographer_ref);
-  Cryptographer* cryptographer = scoped_cryptographer_ref.Get();
-  if (CanCommitItems(cryptographer))
-    nudge_handler_->NudgeForCommit(type_);
-}
-
 // UpdateHandler implementation.
 void ModelTypeSyncWorkerImpl::GetDownloadProgress(
     sync_pb::DataTypeProgressMarker* progress_marker) const {
@@ -109,14 +66,7 @@ SyncerError ModelTypeSyncWorkerImpl::ProcessGetUpdatesResponse(
   data_type_state_.type_context = mutated_context;
   data_type_state_.progress_marker = progress_marker;
 
-  ScopedCryptographerRef scoped_cryptographer_ref;
-  cryptographer_provider_->InitScopedCryptographerRef(
-      &scoped_cryptographer_ref);
-  Cryptographer* cryptographer = scoped_cryptographer_ref.Get();
-  DCHECK(cryptographer);
-
   UpdateResponseDataList response_datas;
-  UpdateResponseDataList pending_updates;
 
   for (SyncEntityList::const_iterator update_it = applicable_updates.begin();
        update_it != applicable_updates.end();
@@ -136,17 +86,16 @@ SyncerError ModelTypeSyncWorkerImpl::ProcessGetUpdatesResponse(
       const std::string& client_tag_hash =
           update_entity->client_defined_unique_tag();
       DCHECK(!client_tag_hash.empty());
-
-      EntityTracker* entity_tracker = NULL;
       EntityMap::const_iterator map_it = entities_.find(client_tag_hash);
       if (map_it == entities_.end()) {
-        entity_tracker =
+        EntityTracker* entity =
             EntityTracker::FromServerUpdate(update_entity->id_string(),
                                             client_tag_hash,
                                             update_entity->version());
-        entities_.insert(std::make_pair(client_tag_hash, entity_tracker));
+        entities_.insert(std::make_pair(client_tag_hash, entity));
       } else {
-        entity_tracker = map_it->second;
+        EntityTracker* entity = map_it->second;
+        entity->ReceiveUpdate(update_entity->version());
       }
 
       // Prepare the message for the model thread.
@@ -158,39 +107,14 @@ SyncerError ModelTypeSyncWorkerImpl::ProcessGetUpdatesResponse(
       response_data.mtime = ProtoTimeToTime(update_entity->mtime());
       response_data.non_unique_name = update_entity->name();
       response_data.deleted = update_entity->deleted();
+      response_data.specifics = update_entity->specifics();
 
-      const sync_pb::EntitySpecifics& specifics = update_entity->specifics();
-
-      if (!specifics.has_encrypted()) {
-        // No encryption.
-        entity_tracker->ReceiveUpdate(update_entity->version());
-        response_data.specifics = specifics;
-        response_datas.push_back(response_data);
-      } else if (specifics.has_encrypted() &&
-                 cryptographer->CanDecrypt(specifics.encrypted())) {
-        // Encrypted, but we know the key.
-        if (DecryptSpecifics(
-                cryptographer, specifics, &response_data.specifics)) {
-          entity_tracker->ReceiveUpdate(update_entity->version());
-          response_data.encryption_key_name = specifics.encrypted().key_name();
-          response_datas.push_back(response_data);
-        }
-      } else if (specifics.has_encrypted() &&
-                 !cryptographer->CanDecrypt(specifics.encrypted())) {
-        // Can't decrypt right now.  Ask the entity tracker to handle it.
-        response_data.specifics = specifics;
-        if (entity_tracker->ReceivePendingUpdate(response_data)) {
-          // Send to the model thread for safe-keeping across restarts if the
-          // tracker decides the update is worth keeping.
-          pending_updates.push_back(response_data);
-        }
-      }
+      response_datas.push_back(response_data);
     }
   }
 
   // Forward these updates to the model thread so it can do the rest.
-  type_sync_proxy_->OnUpdateReceived(
-      data_type_state_, response_datas, pending_updates);
+  type_sync_proxy_->OnUpdateReceived(data_type_state_, response_datas);
 
   return SYNCER_OK;
 }
@@ -204,8 +128,8 @@ void ModelTypeSyncWorkerImpl::ApplyUpdates(sessions::StatusController* status) {
   if (!data_type_state_.initial_sync_done) {
     data_type_state_.initial_sync_done = true;
 
-    type_sync_proxy_->OnUpdateReceived(
-        data_type_state_, UpdateResponseDataList(), UpdateResponseDataList());
+    UpdateResponseDataList empty_update_list;
+    type_sync_proxy_->OnUpdateReceived(data_type_state_, empty_update_list);
   }
 }
 
@@ -220,7 +144,7 @@ void ModelTypeSyncWorkerImpl::EnqueueForCommit(
     const CommitRequestDataList& list) {
   DCHECK(CalledOnValidThread());
 
-  DCHECK(IsTypeInitialized())
+  DCHECK(CanCommitItems())
       << "Asked to commit items before type was initialized.  "
       << "ModelType is: " << ModelTypeToString(type_);
 
@@ -229,13 +153,6 @@ void ModelTypeSyncWorkerImpl::EnqueueForCommit(
        ++it) {
     StorePendingCommit(*it);
   }
-
-  ScopedCryptographerRef scoped_cryptographer_ref;
-  cryptographer_provider_->InitScopedCryptographerRef(
-      &scoped_cryptographer_ref);
-  Cryptographer* cryptographer = scoped_cryptographer_ref.Get();
-  if (CanCommitItems(cryptographer))
-    nudge_handler_->NudgeForCommit(type_);
 }
 
 // CommitContributor implementation.
@@ -247,12 +164,7 @@ scoped_ptr<CommitContribution> ModelTypeSyncWorkerImpl::GetContribution(
   std::vector<int64> sequence_numbers;
   google::protobuf::RepeatedPtrField<sync_pb::SyncEntity> commit_entities;
 
-  ScopedCryptographerRef scoped_cryptographer_ref;
-  cryptographer_provider_->InitScopedCryptographerRef(
-      &scoped_cryptographer_ref);
-  Cryptographer* cryptographer = scoped_cryptographer_ref.Get();
-
-  if (!CanCommitItems(cryptographer))
+  if (!CanCommitItems())
     return scoped_ptr<CommitContribution>();
 
   // TODO(rlarocque): Avoid iterating here.
@@ -265,7 +177,7 @@ scoped_ptr<CommitContribution> ModelTypeSyncWorkerImpl::GetContribution(
       int64 sequence_number = -1;
 
       entity->PrepareCommitProto(commit_entity, &sequence_number);
-      HelpInitializeCommitEntity(cryptographer, commit_entity);
+      HelpInitializeCommitEntity(commit_entity);
       sequence_numbers.push_back(sequence_number);
 
       space_remaining--;
@@ -310,6 +222,9 @@ void ModelTypeSyncWorkerImpl::StorePendingCommit(
                           request.deleted,
                           request.specifics);
   }
+
+  if (CanCommitItems())
+    nudge_handler_->NudgeForCommit(type_);
 }
 
 void ModelTypeSyncWorkerImpl::OnCommitResponse(
@@ -345,30 +260,14 @@ base::WeakPtr<ModelTypeSyncWorkerImpl> ModelTypeSyncWorkerImpl::AsWeakPtr() {
   return weak_ptr_factory_.GetWeakPtr();
 }
 
-bool ModelTypeSyncWorkerImpl::IsTypeInitialized() const {
-  return !data_type_state_.type_root_id.empty() &&
-         data_type_state_.initial_sync_done;
-}
-
-bool ModelTypeSyncWorkerImpl::CanCommitItems(
-    Cryptographer* cryptographer) const {
+bool ModelTypeSyncWorkerImpl::CanCommitItems() const {
   // We can't commit anything until we know the type's parent node.
   // We'll get it in the first update response.
-  if (!IsTypeInitialized())
-    return false;
-
-  // Don't commit if we should be encrypting but don't have the required keys.
-  if (IsEncryptionRequired() && (!cryptographer || !cryptographer->is_ready() ||
-                                 cryptographer->GetDefaultNigoriKeyName() !=
-                                     data_type_state_.encryption_key_name)) {
-    return false;
-  }
-
-  return true;
+  return !data_type_state_.type_root_id.empty() &&
+         data_type_state_.initial_sync_done;
 }
 
 void ModelTypeSyncWorkerImpl::HelpInitializeCommitEntity(
-    Cryptographer* cryptographer,
     sync_pb::SyncEntity* sync_entity) {
   // Initial commits need our help to generate a client ID.
   if (!sync_entity->has_id_string()) {
@@ -378,80 +277,14 @@ void ModelTypeSyncWorkerImpl::HelpInitializeCommitEntity(
         base::StringPrintf("%s-%" PRId64, ModelTypeToString(type_), id));
   }
 
-  // Encrypt the specifics and hide the title if necessary.
-  if (IsEncryptionRequired()) {
-    sync_pb::EntitySpecifics encrypted_specifics;
-    cryptographer->Encrypt(sync_entity->specifics(),
-                           encrypted_specifics.mutable_encrypted());
-    sync_entity->mutable_specifics()->CopyFrom(encrypted_specifics);
-    sync_entity->set_name("encrypted");
-  }
-
   // Always include enough specifics to identify the type.  Do this even in
   // deletion requests, where the specifics are otherwise invalid.
-  AddDefaultFieldValue(type_, sync_entity->mutable_specifics());
+  if (!sync_entity->has_specifics()) {
+    AddDefaultFieldValue(type_, sync_entity->mutable_specifics());
+  }
 
   // We're always responsible for the parent ID.
   sync_entity->set_parent_id_string(data_type_state_.type_root_id);
 }
 
-void ModelTypeSyncWorkerImpl::TryDecryptPendingUpdates() {
-  UpdateResponseDataList response_datas;
-
-  ScopedCryptographerRef scoped_cryptographer_ref;
-  cryptographer_provider_->InitScopedCryptographerRef(
-      &scoped_cryptographer_ref);
-  Cryptographer* cryptographer = scoped_cryptographer_ref.Get();
-  DCHECK(cryptographer);
-
-  for (EntityMap::const_iterator it = entities_.begin(); it != entities_.end();
-       ++it) {
-    if (it->second->HasPendingUpdate()) {
-      const UpdateResponseData& saved_pending = it->second->GetPendingUpdate();
-
-      // We assume all pending updates are encrypted items for which we
-      // don't have the key.
-      DCHECK(saved_pending.specifics.has_encrypted());
-
-      if (cryptographer->CanDecrypt(saved_pending.specifics.encrypted())) {
-        UpdateResponseData decrypted_response = saved_pending;
-        if (DecryptSpecifics(cryptographer,
-                             saved_pending.specifics,
-                             &decrypted_response.specifics)) {
-          decrypted_response.encryption_key_name =
-              saved_pending.specifics.encrypted().key_name();
-          response_datas.push_back(decrypted_response);
-
-          it->second->ClearPendingUpdate();
-        }
-      }
-    }
-  }
-
-  if (!response_datas.empty()) {
-    type_sync_proxy_->OnUpdateReceived(
-        data_type_state_, response_datas, UpdateResponseDataList());
-  }
-}
-
-bool ModelTypeSyncWorkerImpl::DecryptSpecifics(
-    Cryptographer* cryptographer,
-    const sync_pb::EntitySpecifics& in,
-    sync_pb::EntitySpecifics* out) {
-  DCHECK(in.has_encrypted());
-  DCHECK(cryptographer->CanDecrypt(in.encrypted()));
-
-  std::string plaintext;
-  plaintext = cryptographer->DecryptToString(in.encrypted());
-  if (plaintext.empty()) {
-    LOG(ERROR) << "Failed to decrypt a decryptable entity";
-    return false;
-  }
-  if (!out->ParseFromString(plaintext)) {
-    LOG(ERROR) << "Failed to parse decrypted entity";
-    return false;
-  }
-  return true;
-}
-
 }  // namespace syncer
diff --git a/sync/engine/model_type_sync_worker_impl.h b/sync/engine/model_type_sync_worker_impl.h
index f2df976..6905c50 100644
--- a/sync/engine/model_type_sync_worker_impl.h
+++ b/sync/engine/model_type_sync_worker_impl.h
@@ -10,13 +10,11 @@
 #include "base/threading/non_thread_safe.h"
 #include "sync/base/sync_export.h"
 #include "sync/engine/commit_contributor.h"
-#include "sync/engine/cryptographer_provider.h"
 #include "sync/engine/model_type_sync_worker.h"
 #include "sync/engine/nudge_handler.h"
 #include "sync/engine/update_handler.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/non_blocking_sync_common.h"
-#include "sync/internal_api/public/sync_encryption_handler.h"
 #include "sync/protocol/sync.pb.h"
 
 namespace base {
@@ -55,19 +53,12 @@ class SYNC_EXPORT ModelTypeSyncWorkerImpl : public UpdateHandler,
  public:
   ModelTypeSyncWorkerImpl(ModelType type,
                           const DataTypeState& initial_state,
-                          const UpdateResponseDataList& saved_pending_updates,
-                          CryptographerProvider* cryptographer_provider,
                           NudgeHandler* nudge_handler,
                           scoped_ptr<ModelTypeSyncProxy> type_sync_proxy);
   virtual ~ModelTypeSyncWorkerImpl();
 
   ModelType GetModelType() const;
 
-  bool IsEncryptionRequired() const;
-  void SetEncryptionKeyName(const std::string& name);
-
-  void OnCryptographerStateChanged();
-
   // UpdateHandler implementation.
   virtual void GetDownloadProgress(
       sync_pb::DataTypeProgressMarker* progress_marker) const OVERRIDE;
@@ -96,45 +87,20 @@ class SYNC_EXPORT ModelTypeSyncWorkerImpl : public UpdateHandler,
 
  private:
   typedef std::map<std::string, EntityTracker*> EntityMap;
-  typedef std::map<std::string, UpdateResponseData*> UpdateMap;
 
   // Stores a single commit request in this object's internal state.
   void StorePendingCommit(const CommitRequestData& request);
 
-  // Returns true if this type has successfully fetched all available updates
-  // from the server at least once.  Our state may or may not be stale, but at
-  // least we know that it was valid at some point in the past.
-  bool IsTypeInitialized() const;
-
-  // Returns true if this type is prepared to commit items.  Currently, this
-  // depends on having downloaded the initial data and having the encryption
-  // settings in a good state.
-  bool CanCommitItems(Cryptographer* cryptographer) const;
+  // Returns true if all data type state required for commits is available.  In
+  // practice, this means that it returns true from the time this object first
+  // receives notice of a successful update fetch from the server.
+  bool CanCommitItems() const;
 
   // Initializes the parts of a commit entity that are the responsibility of
   // this class, and not the EntityTracker.  Some fields, like the
   // client-assigned ID, can only be set by an entity with knowledge of the
   // entire data type's state.
-  void HelpInitializeCommitEntity(Cryptographer* cryptographer,
-                                  sync_pb::SyncEntity* commit_entity);
-
-  // Attempts to decrypt pending updates stored in the EntityMap.  If
-  // successful, will remove the update from the its EntityTracker and forward
-  // it to the proxy thread for application.
-  void TryDecryptPendingUpdates();
-
-  // Attempts to decrypt the given specifics and return them in the |out|
-  // parameter.  Assumes cryptographer->CanDecrypt(specifics) returned true.
-  //
-  // Returns false if the decryption failed.  There are no guarantees about the
-  // contents of |out| when that happens.
-  //
-  // In theory, this should never fail.  Only corrupt or invalid entries could
-  // cause this to fail, and no clients are known to create such entries.  The
-  // failure case is an attempt to be defensive against bad input.
-  static bool DecryptSpecifics(Cryptographer* cryptographer,
-                               const sync_pb::EntitySpecifics& in,
-                               sync_pb::EntitySpecifics* out);
+  void HelpInitializeCommitEntity(sync_pb::SyncEntity* commit_entity);
 
   ModelType type_;
 
@@ -145,10 +111,6 @@ class SYNC_EXPORT ModelTypeSyncWorkerImpl : public UpdateHandler,
   // This is NULL when no proxy is connected..
   scoped_ptr<ModelTypeSyncProxy> type_sync_proxy_;
 
-  // A helper to provide access to the syncable::Directory's cryptographer.
-  // Not owned.
-  CryptographerProvider* cryptographer_provider_;
-
   // Interface used to access and send nudges to the sync scheduler.  Not owned.
   NudgeHandler* nudge_handler_;
 
diff --git a/sync/engine/model_type_sync_worker_impl_unittest.cc b/sync/engine/model_type_sync_worker_impl_unittest.cc
index df2ed66..0c1fa13 100644
--- a/sync/engine/model_type_sync_worker_impl_unittest.cc
+++ b/sync/engine/model_type_sync_worker_impl_unittest.cc
@@ -4,7 +4,6 @@
 
 #include "sync/engine/model_type_sync_worker_impl.h"
 
-#include "base/strings/stringprintf.h"
 #include "sync/engine/commit_contribution.h"
 #include "sync/engine/model_type_sync_proxy.h"
 #include "sync/internal_api/public/base/model_type.h"
@@ -14,18 +13,13 @@
 #include "sync/syncable/syncable_util.h"
 #include "sync/test/engine/mock_model_type_sync_proxy.h"
 #include "sync/test/engine/mock_nudge_handler.h"
-#include "sync/test/engine/simple_cryptographer_provider.h"
 #include "sync/test/engine/single_type_mock_server.h"
-#include "sync/test/fake_encryptor.h"
 
 #include "testing/gtest/include/gtest/gtest.h"
 
 static const std::string kTypeParentId = "PrefsRootNodeID";
 static const syncer::ModelType kModelType = syncer::PREFERENCES;
 
-// Special constant value taken from cryptographer.cc.
-const char kNigoriKeyName[] = "nigori-key";
-
 namespace syncer {
 
 // Tests the ModelTypeSyncWorkerImpl.
@@ -71,23 +65,8 @@ class ModelTypeSyncWorkerImplTest : public ::testing::Test {
   // committing items right away.
   void NormalInitialize();
 
-  // Initialize with some saved pending updates from the model thread.
-  void InitializeWithPendingUpdates(
-      const UpdateResponseDataList& initial_pending_updates);
-
-  // Initialize with a custom initial DataTypeState and pending updates.
-  void InitializeWithState(const DataTypeState& state,
-                           const UpdateResponseDataList& pending_updates);
-
-  // Introduce a new key that the local cryptographer can't decrypt.
-  void NewForeignEncryptionKey();
-
-  // Update the local cryptographer with all relevant keys.
-  void UpdateLocalCryptographer();
-
-  // Use the Nth nigori instance to encrypt incoming updates.
-  // The default value, zero, indicates no encryption.
-  void SetUpdateEncryptionFilter(int n);
+  // Initialize with a custom initial DataTypeState.
+  void InitializeWithState(const DataTypeState& state);
 
   // Modifications on the model thread that get sent to the worker under test.
   void CommitRequest(const std::string& tag, const std::string& value);
@@ -100,13 +79,6 @@ class ModelTypeSyncWorkerImplTest : public ::testing::Test {
                                const std::string& value);
   void TriggerTombstoneFromServer(int64 version_offset, const std::string& tag);
 
-  // Delivers specified protos as updates.
-  //
-  // Does not update mock server state.  Should be used as a last resort when
-  // writing test cases that require entities that don't fit the normal sync
-  // protocol.  Try to use the other, higher level methods if possible.
-  void DeliverRawUpdates(const SyncEntityList& update_list);
-
   // By default, this harness behaves as if all tasks posted to the model
   // thread are executed immediately.  However, this is not necessarily true.
   // The model's TaskRunner has a queue, and the tasks we post to it could
@@ -138,7 +110,6 @@ class ModelTypeSyncWorkerImplTest : public ::testing::Test {
   // be updated until the response is actually processed by the model thread.
   size_t GetNumModelThreadUpdateResponses() const;
   UpdateResponseDataList GetNthModelThreadUpdateResponse(size_t n) const;
-  UpdateResponseDataList GetNthModelThreadPendingUpdates(size_t n) const;
   DataTypeState GetNthModelThreadUpdateState(size_t n) const;
 
   // Reads the latest update response datas on the model thread.
@@ -173,39 +144,7 @@ class ModelTypeSyncWorkerImplTest : public ::testing::Test {
   static sync_pb::EntitySpecifics GenerateSpecifics(const std::string& tag,
                                                     const std::string& value);
 
-  // Returns a set of KeyParams for the cryptographer.  Each input 'n' value
-  // results in a different set of parameters.
-  static KeyParams GetNthKeyParams(int n);
-
-  // Returns the name for the given Nigori.
-  //
-  // Uses some 'white-box' knowledge to mimic the names that a real sync client
-  // would generate.  It's probably not necessary to do so, but it can't hurt.
-  static std::string GetNigoriName(const Nigori& nigori);
-
-  // Modifies the input/output parameter |specifics| by encrypting it with
-  // a Nigori intialized with the specified KeyParams.
-  static void EncryptUpdate(const KeyParams& params,
-                            sync_pb::EntitySpecifics* specifics);
-
  private:
-  // An encryptor for our cryptographer.
-  FakeEncryptor fake_encryptor_;
-
-  // The cryptographer itself.
-  Cryptographer cryptographer_;
-
-  // A CryptographerProvider for the ModelTypeSyncWorkerImpl.
-  SimpleCryptographerProvider cryptographer_provider_;
-
-  // The number of the most recent foreign encryption key known to our
-  // cryptographer.  Note that not all of these will be decryptable.
-  int foreign_encryption_key_index_;
-
-  // The number of the encryption key used to encrypt incoming updates.  A zero
-  // value implies no encryption.
-  int update_encryption_filter_index_;
-
   // The ModelTypeSyncWorkerImpl being tested.
   scoped_ptr<ModelTypeSyncWorkerImpl> worker_;
 
@@ -224,12 +163,7 @@ class ModelTypeSyncWorkerImplTest : public ::testing::Test {
 };
 
 ModelTypeSyncWorkerImplTest::ModelTypeSyncWorkerImplTest()
-    : cryptographer_(&fake_encryptor_),
-      cryptographer_provider_(&cryptographer_),
-      foreign_encryption_key_index_(0),
-      update_encryption_filter_index_(0),
-      mock_type_sync_proxy_(NULL),
-      mock_server_(kModelType) {
+    : mock_type_sync_proxy_(NULL), mock_server_(kModelType) {
 }
 
 ModelTypeSyncWorkerImplTest::~ModelTypeSyncWorkerImplTest() {
@@ -241,15 +175,10 @@ void ModelTypeSyncWorkerImplTest::FirstInitialize() {
       GetSpecificsFieldNumberFromModelType(kModelType));
   initial_state.next_client_id = 0;
 
-  InitializeWithState(initial_state, UpdateResponseDataList());
+  InitializeWithState(initial_state);
 }
 
 void ModelTypeSyncWorkerImplTest::NormalInitialize() {
-  InitializeWithPendingUpdates(UpdateResponseDataList());
-}
-
-void ModelTypeSyncWorkerImplTest::InitializeWithPendingUpdates(
-    const UpdateResponseDataList& initial_pending_updates) {
   DataTypeState initial_state;
   initial_state.progress_marker.set_data_type_id(
       GetSpecificsFieldNumberFromModelType(kModelType));
@@ -259,79 +188,21 @@ void ModelTypeSyncWorkerImplTest::InitializeWithPendingUpdates(
   initial_state.type_root_id = kTypeParentId;
   initial_state.initial_sync_done = true;
 
-  InitializeWithState(initial_state, initial_pending_updates);
+  InitializeWithState(initial_state);
 
   mock_nudge_handler_.ClearCounters();
 }
 
 void ModelTypeSyncWorkerImplTest::InitializeWithState(
-    const DataTypeState& state,
-    const UpdateResponseDataList& initial_pending_updates) {
+    const DataTypeState& state) {
   DCHECK(!worker_);
 
   // We don't get to own this object.  The |worker_| keeps a scoped_ptr to it.
   mock_type_sync_proxy_ = new MockModelTypeSyncProxy();
   scoped_ptr<ModelTypeSyncProxy> proxy(mock_type_sync_proxy_);
 
-  worker_.reset(new ModelTypeSyncWorkerImpl(kModelType,
-                                            state,
-                                            initial_pending_updates,
-                                            &cryptographer_provider_,
-                                            &mock_nudge_handler_,
-                                            proxy.Pass()));
-}
-
-void ModelTypeSyncWorkerImplTest::NewForeignEncryptionKey() {
-  foreign_encryption_key_index_++;
-
-  sync_pb::NigoriKeyBag bag;
-
-  for (int i = 0; i <= foreign_encryption_key_index_; ++i) {
-    Nigori nigori;
-    KeyParams params = GetNthKeyParams(i);
-    nigori.InitByDerivation(params.hostname, params.username, params.password);
-
-    sync_pb::NigoriKey* key = bag.add_key();
-
-    key->set_name(GetNigoriName(nigori));
-    nigori.ExportKeys(key->mutable_user_key(),
-                      key->mutable_encryption_key(),
-                      key->mutable_mac_key());
-  }
-
-  // Re-create the last nigori from that loop.
-  Nigori last_nigori;
-  KeyParams params = GetNthKeyParams(foreign_encryption_key_index_);
-  last_nigori.InitByDerivation(
-      params.hostname, params.username, params.password);
-
-  // Serialize and encrypt the bag with the last nigori.
-  std::string serialized_bag;
-  bag.SerializeToString(&serialized_bag);
-
-  sync_pb::EncryptedData encrypted;
-  encrypted.set_key_name(GetNigoriName(last_nigori));
-  last_nigori.Encrypt(serialized_bag, encrypted.mutable_blob());
-
-  // Update the cryptographer with new pending keys.
-  cryptographer_.SetPendingKeys(encrypted);
-
-  // Update the worker with the latest encryption key name.
-  if (worker_)
-    worker_->SetEncryptionKeyName(encrypted.key_name());
-}
-
-void ModelTypeSyncWorkerImplTest::UpdateLocalCryptographer() {
-  KeyParams params = GetNthKeyParams(foreign_encryption_key_index_);
-  bool success = cryptographer_.DecryptPendingKeys(params);
-  DCHECK(success);
-
-  if (worker_)
-    worker_->OnCryptographerStateChanged();
-}
-
-void ModelTypeSyncWorkerImplTest::SetUpdateEncryptionFilter(int n) {
-  update_encryption_filter_index_ = n;
+  worker_.reset(new ModelTypeSyncWorkerImpl(
+      kModelType, state, &mock_nudge_handler_, proxy.Pass()));
 }
 
 void ModelTypeSyncWorkerImplTest::CommitRequest(const std::string& name,
@@ -372,12 +243,6 @@ void ModelTypeSyncWorkerImplTest::TriggerUpdateFromServer(
     const std::string& value) {
   sync_pb::SyncEntity entity = mock_server_.UpdateFromServer(
       version_offset, GenerateTagHash(tag), GenerateSpecifics(tag, value));
-
-  if (update_encryption_filter_index_ != 0) {
-    EncryptUpdate(GetNthKeyParams(update_encryption_filter_index_),
-                  entity.mutable_specifics());
-  }
-
   SyncEntityList entity_list;
   entity_list.push_back(&entity);
 
@@ -390,27 +255,11 @@ void ModelTypeSyncWorkerImplTest::TriggerUpdateFromServer(
   worker_->ApplyUpdates(&dummy_status);
 }
 
-void ModelTypeSyncWorkerImplTest::DeliverRawUpdates(
-    const SyncEntityList& list) {
-  sessions::StatusController dummy_status;
-  worker_->ProcessGetUpdatesResponse(mock_server_.GetProgress(),
-                                     mock_server_.GetContext(),
-                                     list,
-                                     &dummy_status);
-  worker_->ApplyUpdates(&dummy_status);
-}
-
 void ModelTypeSyncWorkerImplTest::TriggerTombstoneFromServer(
     int64 version_offset,
     const std::string& tag) {
   sync_pb::SyncEntity entity =
       mock_server_.TombstoneFromServer(version_offset, GenerateTagHash(tag));
-
-  if (update_encryption_filter_index_ != 0) {
-    EncryptUpdate(GetNthKeyParams(update_encryption_filter_index_),
-                  entity.mutable_specifics());
-  }
-
   SyncEntityList entity_list;
   entity_list.push_back(&entity);
 
@@ -497,12 +346,6 @@ ModelTypeSyncWorkerImplTest::GetNthModelThreadUpdateResponse(size_t n) const {
   return mock_type_sync_proxy_->GetNthUpdateResponse(n);
 }
 
-UpdateResponseDataList
-ModelTypeSyncWorkerImplTest::GetNthModelThreadPendingUpdates(size_t n) const {
-  DCHECK_LT(n, GetNumModelThreadUpdateResponses());
-  return mock_type_sync_proxy_->GetNthPendingUpdates(n);
-}
-
 DataTypeState ModelTypeSyncWorkerImplTest::GetNthModelThreadUpdateState(
     size_t n) const {
   DCHECK_LT(n, GetNumModelThreadUpdateResponses());
@@ -558,7 +401,6 @@ int ModelTypeSyncWorkerImplTest::GetNumInitialDownloadNudges() const {
   return mock_nudge_handler_.GetNumInitialDownloadNudges();
 }
 
-// static.
 std::string ModelTypeSyncWorkerImplTest::GenerateTagHash(
     const std::string& tag) {
   const std::string& client_tag_hash =
@@ -566,7 +408,6 @@ std::string ModelTypeSyncWorkerImplTest::GenerateTagHash(
   return client_tag_hash;
 }
 
-// static.
 sync_pb::EntitySpecifics ModelTypeSyncWorkerImplTest::GenerateSpecifics(
     const std::string& tag,
     const std::string& value) {
@@ -576,46 +417,6 @@ sync_pb::EntitySpecifics ModelTypeSyncWorkerImplTest::GenerateSpecifics(
   return specifics;
 }
 
-// static.
-std::string ModelTypeSyncWorkerImplTest::GetNigoriName(const Nigori& nigori) {
-  std::string name;
-  if (!nigori.Permute(Nigori::Password, kNigoriKeyName, &name)) {
-    NOTREACHED();
-    return std::string();
-  }
-
-  return name;
-}
-
-// static.
-KeyParams ModelTypeSyncWorkerImplTest::GetNthKeyParams(int n) {
-  KeyParams params;
-  params.hostname = std::string("localhost");
-  params.username = std::string("userX");
-  params.password = base::StringPrintf("pw%02d", n);
-  return params;
-}
-
-// static.
-void ModelTypeSyncWorkerImplTest::EncryptUpdate(
-    const KeyParams& params,
-    sync_pb::EntitySpecifics* specifics) {
-  Nigori nigori;
-  nigori.InitByDerivation(params.hostname, params.username, params.password);
-
-  sync_pb::EntitySpecifics original_specifics = *specifics;
-  std::string plaintext;
-  original_specifics.SerializeToString(&plaintext);
-
-  std::string encrypted;
-  nigori.Encrypt(plaintext, &encrypted);
-
-  specifics->Clear();
-  AddDefaultFieldValue(kModelType, specifics);
-  specifics->mutable_encrypted()->set_key_name(GetNigoriName(nigori));
-  specifics->mutable_encrypted()->set_blob(encrypted);
-}
-
 // Requests a commit and verifies the messages sent to the client and server as
 // a result.
 //
@@ -799,7 +600,6 @@ TEST_F(ModelTypeSyncWorkerImplTest, TwoNewItemsCommittedSeparately) {
   EXPECT_EQ(2U, GetNumModelThreadCommitResponses());
 }
 
-// Test normal update receipt code path.
 TEST_F(ModelTypeSyncWorkerImplTest, ReceiveUpdates) {
   NormalInitialize();
 
@@ -825,281 +625,4 @@ TEST_F(ModelTypeSyncWorkerImplTest, ReceiveUpdates) {
   EXPECT_EQ("value1", update.specifics.preference().value());
 }
 
-// Test commit of encrypted updates.
-TEST_F(ModelTypeSyncWorkerImplTest, EncryptedCommit) {
-  NormalInitialize();
-
-  NewForeignEncryptionKey();
-  UpdateLocalCryptographer();
-
-  // Normal commit request stuff.
-  CommitRequest("tag1", "value1");
-  DoSuccessfulCommit();
-  ASSERT_EQ(1U, GetNumCommitMessagesOnServer());
-  EXPECT_EQ(1, GetNthCommitMessageOnServer(0).commit().entries_size());
-  ASSERT_TRUE(HasCommitEntityOnServer("tag1"));
-  const sync_pb::SyncEntity& tag1_entity =
-      GetLatestCommitEntityOnServer("tag1");
-
-  EXPECT_TRUE(tag1_entity.specifics().has_encrypted());
-
-  // The title should be overwritten.
-  EXPECT_EQ(tag1_entity.name(), "encrypted");
-
-  // The type should be set, but there should be no non-encrypted contents.
-  EXPECT_TRUE(tag1_entity.specifics().has_preference());
-  EXPECT_FALSE(tag1_entity.specifics().preference().has_name());
-  EXPECT_FALSE(tag1_entity.specifics().preference().has_value());
-}
-
-// Test items are not committed when encryption is required but unavailable.
-TEST_F(ModelTypeSyncWorkerImplTest, EncryptionBlocksCommits) {
-  NormalInitialize();
-
-  CommitRequest("tag1", "value1");
-  EXPECT_TRUE(WillCommit());
-
-  // We know encryption is in use on this account, but don't have the necessary
-  // encryption keys.  The worker should refuse to commit.
-  NewForeignEncryptionKey();
-  EXPECT_FALSE(WillCommit());
-
-  // Once the cryptographer is returned to a normal state, we should be able to
-  // commit again.
-  EXPECT_EQ(1, GetNumCommitNudges());
-  UpdateLocalCryptographer();
-  EXPECT_EQ(2, GetNumCommitNudges());
-  EXPECT_TRUE(WillCommit());
-
-  // Verify the committed entity was properly encrypted.
-  DoSuccessfulCommit();
-  ASSERT_EQ(1U, GetNumCommitMessagesOnServer());
-  EXPECT_EQ(1, GetNthCommitMessageOnServer(0).commit().entries_size());
-  ASSERT_TRUE(HasCommitEntityOnServer("tag1"));
-  const sync_pb::SyncEntity& tag1_entity =
-      GetLatestCommitEntityOnServer("tag1");
-  EXPECT_TRUE(tag1_entity.specifics().has_encrypted());
-  EXPECT_EQ(tag1_entity.name(), "encrypted");
-  EXPECT_TRUE(tag1_entity.specifics().has_preference());
-  EXPECT_FALSE(tag1_entity.specifics().preference().has_name());
-  EXPECT_FALSE(tag1_entity.specifics().preference().has_value());
-}
-
-// Test the receipt of decryptable entities.
-TEST_F(ModelTypeSyncWorkerImplTest, ReceiveDecryptableEntities) {
-  NormalInitialize();
-
-  // Create a new Nigori and allow the cryptographer to decrypt it.
-  NewForeignEncryptionKey();
-  UpdateLocalCryptographer();
-
-  // First, receive an unencrypted entry.
-  TriggerUpdateFromServer(10, "tag1", "value1");
-
-  // Test some basic properties regarding the update.
-  ASSERT_TRUE(HasUpdateResponseOnModelThread("tag1"));
-  UpdateResponseData update1 = GetUpdateResponseOnModelThread("tag1");
-  EXPECT_EQ("tag1", update1.specifics.preference().name());
-  EXPECT_EQ("value1", update1.specifics.preference().value());
-  EXPECT_TRUE(update1.encryption_key_name.empty());
-
-  // Set received updates to be encrypted using the new nigori.
-  SetUpdateEncryptionFilter(1);
-
-  // This next update will be encrypted.
-  TriggerUpdateFromServer(10, "tag2", "value2");
-
-  // Test its basic features and the value of encryption_key_name.
-  ASSERT_TRUE(HasUpdateResponseOnModelThread("tag2"));
-  UpdateResponseData update2 = GetUpdateResponseOnModelThread("tag2");
-  EXPECT_EQ("tag2", update2.specifics.preference().name());
-  EXPECT_EQ("value2", update2.specifics.preference().value());
-  EXPECT_FALSE(update2.encryption_key_name.empty());
-}
-
-// Receive updates that are initially undecryptable, then ensure they get
-// delivered to the model thread when decryption becomes possible.
-TEST_F(ModelTypeSyncWorkerImplTest, ReceiveUndecryptableEntries) {
-  NormalInitialize();
-
-  // Set a new encryption key.  The model thread will be notified of the new
-  // encryption key through a faked update response.
-  NewForeignEncryptionKey();
-  EXPECT_EQ(1U, GetNumModelThreadUpdateResponses());
-
-  // Send an update using that new key.
-  SetUpdateEncryptionFilter(1);
-  TriggerUpdateFromServer(10, "tag1", "value1");
-
-  // At this point, the cryptographer does not have access to the key, so the
-  // updates will be undecryptable.  They'll be transfered to the model thread
-  // for safe-keeping as pending updates.
-  ASSERT_EQ(2U, GetNumModelThreadUpdateResponses());
-  UpdateResponseDataList updates_list = GetNthModelThreadUpdateResponse(1);
-  EXPECT_EQ(0U, updates_list.size());
-  UpdateResponseDataList pending_updates = GetNthModelThreadPendingUpdates(1);
-  EXPECT_EQ(1U, pending_updates.size());
-
-  // The update will be delivered as soon as decryption becomes possible.
-  UpdateLocalCryptographer();
-  ASSERT_TRUE(HasUpdateResponseOnModelThread("tag1"));
-  UpdateResponseData update = GetUpdateResponseOnModelThread("tag1");
-  EXPECT_EQ("tag1", update.specifics.preference().name());
-  EXPECT_EQ("value1", update.specifics.preference().value());
-  EXPECT_FALSE(update.encryption_key_name.empty());
-}
-
-// Ensure that even encrypted updates can cause conflicts.
-TEST_F(ModelTypeSyncWorkerImplTest, EncryptedUpdateOverridesPendingCommit) {
-  NormalInitialize();
-
-  // Prepeare to commit an item.
-  CommitRequest("tag1", "value1");
-  EXPECT_TRUE(WillCommit());
-
-  // Receive an encrypted update for that item.
-  SetUpdateEncryptionFilter(1);
-  TriggerUpdateFromServer(10, "tag1", "value1");
-
-  // The pending commit state should be cleared.
-  EXPECT_FALSE(WillCommit());
-
-  // The encrypted update will be delivered to the model thread.
-  ASSERT_EQ(1U, GetNumModelThreadUpdateResponses());
-  UpdateResponseDataList updates_list = GetNthModelThreadUpdateResponse(0);
-  EXPECT_EQ(0U, updates_list.size());
-  UpdateResponseDataList pending_updates = GetNthModelThreadPendingUpdates(0);
-  EXPECT_EQ(1U, pending_updates.size());
-}
-
-// Test decryption of pending updates saved across a restart.
-TEST_F(ModelTypeSyncWorkerImplTest, RestorePendingEntries) {
-  // Create a fake pending update.
-  UpdateResponseData update;
-
-  update.client_tag_hash = GenerateTagHash("tag1");
-  update.id = "SomeID";
-  update.response_version = 100;
-  update.ctime = base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(10);
-  update.mtime = base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(11);
-  update.non_unique_name = "encrypted";
-  update.deleted = false;
-
-  update.specifics = GenerateSpecifics("tag1", "value1");
-  EncryptUpdate(GetNthKeyParams(1), &(update.specifics));
-
-  // Inject the update during ModelTypeSyncWorker initialization.
-  UpdateResponseDataList saved_pending_updates;
-  saved_pending_updates.push_back(update);
-  InitializeWithPendingUpdates(saved_pending_updates);
-
-  // Update will be undecryptable at first.
-  EXPECT_EQ(0U, GetNumModelThreadUpdateResponses());
-  ASSERT_FALSE(HasUpdateResponseOnModelThread("tag1"));
-
-  // Update the cryptographer so it can decrypt that update.
-  NewForeignEncryptionKey();
-  UpdateLocalCryptographer();
-
-  // Verify the item gets decrypted and sent back to the model thread.
-  ASSERT_TRUE(HasUpdateResponseOnModelThread("tag1"));
-}
-
-// Test decryption of pending updates saved across a restart.  This test
-// differs from the previous one in that the restored updates can be decrypted
-// immediately after the ModelTypeSyncWorker is constructed.
-TEST_F(ModelTypeSyncWorkerImplTest, RestoreApplicableEntries) {
-  // Update the cryptographer so it can decrypt that update.
-  NewForeignEncryptionKey();
-  UpdateLocalCryptographer();
-
-  // Create a fake pending update.
-  UpdateResponseData update;
-  update.client_tag_hash = GenerateTagHash("tag1");
-  update.id = "SomeID";
-  update.response_version = 100;
-  update.ctime = base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(10);
-  update.mtime = base::Time::UnixEpoch() + base::TimeDelta::FromSeconds(11);
-  update.non_unique_name = "encrypted";
-  update.deleted = false;
-
-  update.specifics = GenerateSpecifics("tag1", "value1");
-  EncryptUpdate(GetNthKeyParams(1), &(update.specifics));
-
-  // Inject the update during ModelTypeSyncWorker initialization.
-  UpdateResponseDataList saved_pending_updates;
-  saved_pending_updates.push_back(update);
-  InitializeWithPendingUpdates(saved_pending_updates);
-
-  // Verify the item gets decrypted and sent back to the model thread.
-  ASSERT_TRUE(HasUpdateResponseOnModelThread("tag1"));
-}
-
-// Test that undecryptable updates provide sufficient reason to not commit.
-//
-// This should be rare in practice.  Usually the cryptographer will be in an
-// unusable state when we receive undecryptable updates, and that alone will be
-// enough to prevent all commits.
-TEST_F(ModelTypeSyncWorkerImplTest, CommitBlockedByPending) {
-  NormalInitialize();
-
-  // Prepeare to commit an item.
-  CommitRequest("tag1", "value1");
-  EXPECT_TRUE(WillCommit());
-
-  // Receive an encrypted update for that item.
-  SetUpdateEncryptionFilter(1);
-  TriggerUpdateFromServer(10, "tag1", "value1");
-
-  // The pending commit state should be cleared.
-  EXPECT_FALSE(WillCommit());
-
-  // The pending update will be delivered to the model thread.
-  HasUpdateResponseOnModelThread("tag1");
-
-  // Pretend the update arrived too late to prevent another commit request.
-  CommitRequest("tag1", "value2");
-
-  EXPECT_FALSE(WillCommit());
-}
-
-// Verify that corrupted encrypted updates don't cause crashes.
-TEST_F(ModelTypeSyncWorkerImplTest, ReceiveCorruptEncryption) {
-  // Initialize the worker with basic encryption state.
-  NormalInitialize();
-  NewForeignEncryptionKey();
-  UpdateLocalCryptographer();
-
-  // Manually create an update.
-  sync_pb::SyncEntity entity;
-  entity.set_client_defined_unique_tag(GenerateTagHash("tag1"));
-  entity.set_id_string("SomeID");
-  entity.set_version(1);
-  entity.set_ctime(1000);
-  entity.set_mtime(1001);
-  entity.set_name("encrypted");
-  entity.set_deleted(false);
-
-  // Encrypt it.
-  entity.mutable_specifics()->CopyFrom(GenerateSpecifics("tag1", "value1"));
-  EncryptUpdate(GetNthKeyParams(1), entity.mutable_specifics());
-
-  // Replace a few bytes to corrupt it.
-  entity.mutable_specifics()->mutable_encrypted()->mutable_blob()->replace(
-      0, 4, "xyz!");
-
-  SyncEntityList entity_list;
-  entity_list.push_back(&entity);
-
-  // If a corrupt update could trigger a crash, this is where it would happen.
-  DeliverRawUpdates(entity_list);
-
-  EXPECT_FALSE(HasUpdateResponseOnModelThread("tag1"));
-
-  // Deliver a non-corrupt update to see if the everything still works.
-  SetUpdateEncryptionFilter(1);
-  TriggerUpdateFromServer(10, "tag1", "value1");
-  EXPECT_TRUE(HasUpdateResponseOnModelThread("tag1"));
-}
-
 }  // namespace syncer
diff --git a/sync/internal_api/public/non_blocking_sync_common.h b/sync/internal_api/public/non_blocking_sync_common.h
index b53e6a6..7c7580b 100644
--- a/sync/internal_api/public/non_blocking_sync_common.h
+++ b/sync/internal_api/public/non_blocking_sync_common.h
@@ -38,11 +38,6 @@ struct SYNC_EXPORT_PRIVATE DataTypeState {
   // until the first download cycle has completed.
   std::string type_root_id;
 
-  // This value is set if this type's data should be encrypted on the server.
-  // If this key changes, the client will need to re-commit all of its local
-  // data to the server using the new encryption key.
-  std::string encryption_key_name;
-
   // A strictly increasing counter used to generate unique values for the
   // client-assigned IDs.  The incrementing and ID assignment happens on the
   // sync thread, but we store the value here so we can pass it back to the
@@ -56,6 +51,7 @@ struct SYNC_EXPORT_PRIVATE DataTypeState {
   // flag is set.
   bool initial_sync_done;
 };
+
 struct SYNC_EXPORT_PRIVATE CommitRequestData {
   CommitRequestData();
   ~CommitRequestData();
@@ -98,7 +94,6 @@ struct SYNC_EXPORT_PRIVATE UpdateResponseData {
   std::string non_unique_name;
   bool deleted;
   sync_pb::EntitySpecifics specifics;
-  std::string encryption_key_name;
 };
 
 typedef std::vector<CommitRequestData> CommitRequestDataList;
diff --git a/sync/internal_api/public/sync_context.h b/sync/internal_api/public/sync_context.h
index 12598cd..67b1a41 100644
--- a/sync/internal_api/public/sync_context.h
+++ b/sync/internal_api/public/sync_context.h
@@ -10,11 +10,11 @@
 #include "base/sequenced_task_runner.h"
 #include "sync/base/sync_export.h"
 #include "sync/internal_api/public/base/model_type.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
 
 namespace syncer {
 
 class ModelTypeSyncProxyImpl;
+struct DataTypeState;
 
 // An interface of the core parts of sync.
 //
@@ -35,7 +35,6 @@ class SYNC_EXPORT_PRIVATE SyncContext {
   virtual void ConnectSyncTypeToWorker(
       syncer::ModelType type,
       const DataTypeState& data_type_state,
-      const syncer::UpdateResponseDataList& saved_pending_updates,
       const scoped_refptr<base::SequencedTaskRunner>& datatype_task_runner,
       const base::WeakPtr<ModelTypeSyncProxyImpl>& type_sync_proxy) = 0;
 
diff --git a/sync/internal_api/public/sync_context_proxy.h b/sync/internal_api/public/sync_context_proxy.h
index 230a42a..14bf14f 100644
--- a/sync/internal_api/public/sync_context_proxy.h
+++ b/sync/internal_api/public/sync_context_proxy.h
@@ -7,7 +7,6 @@
 
 #include "base/memory/weak_ptr.h"
 #include "sync/internal_api/public/base/model_type.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
 
 namespace syncer {
 
@@ -28,7 +27,6 @@ class SYNC_EXPORT_PRIVATE SyncContextProxy {
   virtual void ConnectTypeToSync(
       syncer::ModelType type,
       const DataTypeState& data_type_state,
-      const UpdateResponseDataList& saved_pending_updates,
       const base::WeakPtr<ModelTypeSyncProxyImpl>& type_sync_proxy) = 0;
 
   // Tells the syncer that we're no longer interested in syncing this type.
diff --git a/sync/internal_api/public/test/null_sync_context_proxy.h b/sync/internal_api/public/test/null_sync_context_proxy.h
index 0ca080d..808f664 100644
--- a/sync/internal_api/public/test/null_sync_context_proxy.h
+++ b/sync/internal_api/public/test/null_sync_context_proxy.h
@@ -6,7 +6,6 @@
 #define SYNC_INTERNAL_API_PUBLIC_TEST_NULL_SYNC_CONTEXT_PROXY_H_
 
 #include "base/memory/weak_ptr.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
 #include "sync/internal_api/public/sync_context_proxy.h"
 
 namespace syncer {
@@ -24,7 +23,6 @@ class NullSyncContextProxy : public SyncContextProxy {
   virtual void ConnectTypeToSync(
       syncer::ModelType type,
       const DataTypeState& data_type_state,
-      const UpdateResponseDataList& saved_pending_updates,
       const base::WeakPtr<ModelTypeSyncProxyImpl>& type_sync_proxy) OVERRIDE;
   virtual void Disconnect(syncer::ModelType type) OVERRIDE;
   virtual scoped_ptr<SyncContextProxy> Clone() const OVERRIDE;
diff --git a/sync/internal_api/sync_context_proxy_impl.cc b/sync/internal_api/sync_context_proxy_impl.cc
index ee17c72..7d6a817 100644
--- a/sync/internal_api/sync_context_proxy_impl.cc
+++ b/sync/internal_api/sync_context_proxy_impl.cc
@@ -25,7 +25,6 @@ SyncContextProxyImpl::~SyncContextProxyImpl() {
 void SyncContextProxyImpl::ConnectTypeToSync(
     ModelType type,
     const DataTypeState& data_type_state,
-    const UpdateResponseDataList& saved_pending_updates,
     const base::WeakPtr<ModelTypeSyncProxyImpl>& type_sync_proxy) {
   VLOG(1) << "ConnectTypeToSync: " << ModelTypeToString(type);
   sync_task_runner_->PostTask(FROM_HERE,
@@ -33,7 +32,6 @@ void SyncContextProxyImpl::ConnectTypeToSync(
                                          sync_context_,
                                          type,
                                          data_type_state,
-                                         saved_pending_updates,
                                          base::ThreadTaskRunnerHandle::Get(),
                                          type_sync_proxy));
 }
diff --git a/sync/internal_api/sync_context_proxy_impl.h b/sync/internal_api/sync_context_proxy_impl.h
index 7f121a3..fb7cd4f 100644
--- a/sync/internal_api/sync_context_proxy_impl.h
+++ b/sync/internal_api/sync_context_proxy_impl.h
@@ -40,7 +40,6 @@ class SYNC_EXPORT_PRIVATE SyncContextProxyImpl : public SyncContextProxy {
   virtual void ConnectTypeToSync(
       syncer::ModelType type,
       const DataTypeState& data_type_state,
-      const UpdateResponseDataList& pending_updates,
       const base::WeakPtr<ModelTypeSyncProxyImpl>& sync_proxy_impl) OVERRIDE;
 
   // Disables syncing for the given type on the sync thread.
diff --git a/sync/internal_api/sync_encryption_handler_impl.cc b/sync/internal_api/sync_encryption_handler_impl.cc
index aea66e5..3a88f53 100644
--- a/sync/internal_api/sync_encryption_handler_impl.cc
+++ b/sync/internal_api/sync_encryption_handler_impl.cc
@@ -1519,7 +1519,7 @@ bool SyncEncryptionHandlerImpl::GetKeystoreDecryptor(
   DCHECK(!keystore_key.empty());
   DCHECK(cryptographer.is_ready());
   std::string serialized_nigori;
-  serialized_nigori = cryptographer.GetDefaultNigoriKeyData();
+  serialized_nigori = cryptographer.GetDefaultNigoriKey();
   if (serialized_nigori.empty()) {
     LOG(ERROR) << "Failed to get cryptographer bootstrap token.";
     return false;
diff --git a/sync/internal_api/test/null_sync_context_proxy.cc b/sync/internal_api/test/null_sync_context_proxy.cc
index 2fc8bbf..e209c21 100644
--- a/sync/internal_api/test/null_sync_context_proxy.cc
+++ b/sync/internal_api/test/null_sync_context_proxy.cc
@@ -15,7 +15,6 @@ NullSyncContextProxy::~NullSyncContextProxy() {
 void NullSyncContextProxy::ConnectTypeToSync(
     syncer::ModelType type,
     const DataTypeState& data_type_state,
-    const UpdateResponseDataList& saved_pending_updates,
     const base::WeakPtr<ModelTypeSyncProxyImpl>& type_sync_proxy) {
   NOTREACHED() << "NullSyncContextProxy is not meant to be used";
 }
diff --git a/sync/sessions/model_type_registry.cc b/sync/sessions/model_type_registry.cc
index c2ba5f4..5222202 100644
--- a/sync/sessions/model_type_registry.cc
+++ b/sync/sessions/model_type_registry.cc
@@ -15,7 +15,6 @@
 #include "sync/engine/model_type_sync_worker_impl.h"
 #include "sync/internal_api/public/non_blocking_sync_common.h"
 #include "sync/sessions/directory_type_debug_info_emitter.h"
-#include "sync/util/cryptographer.h"
 
 namespace syncer {
 
@@ -33,8 +32,7 @@ class ModelTypeSyncProxyWrapper : public ModelTypeSyncProxy {
       const CommitResponseDataList& response_list) OVERRIDE;
   virtual void OnUpdateReceived(
       const DataTypeState& type_state,
-      const UpdateResponseDataList& response_list,
-      const UpdateResponseDataList& pending_updates) OVERRIDE;
+      const UpdateResponseDataList& response_list) OVERRIDE;
 
  private:
   base::WeakPtr<ModelTypeSyncProxyImpl> processor_;
@@ -63,15 +61,13 @@ void ModelTypeSyncProxyWrapper::OnCommitCompleted(
 
 void ModelTypeSyncProxyWrapper::OnUpdateReceived(
     const DataTypeState& type_state,
-    const UpdateResponseDataList& response_list,
-    const UpdateResponseDataList& pending_updates) {
+    const UpdateResponseDataList& response_list) {
   processor_task_runner_->PostTask(
       FROM_HERE,
       base::Bind(&ModelTypeSyncProxyImpl::OnUpdateReceived,
                  processor_,
                  type_state,
-                 response_list,
-                 pending_updates));
+                 response_list));
 }
 
 class ModelTypeSyncWorkerWrapper : public ModelTypeSyncWorker {
@@ -111,7 +107,6 @@ ModelTypeRegistry::ModelTypeRegistry(
     syncable::Directory* directory,
     NudgeHandler* nudge_handler)
     : directory_(directory),
-      cryptographer_provider_(directory_),
       nudge_handler_(nudge_handler),
       weak_ptr_factory_(this) {
   for (size_t i = 0u; i < workers.size(); ++i) {
@@ -190,7 +185,6 @@ void ModelTypeRegistry::SetEnabledDirectoryTypes(
 void ModelTypeRegistry::ConnectSyncTypeToWorker(
     ModelType type,
     const DataTypeState& data_type_state,
-    const UpdateResponseDataList& saved_pending_updates,
     const scoped_refptr<base::SequencedTaskRunner>& type_task_runner,
     const base::WeakPtr<ModelTypeSyncProxyImpl>& proxy_impl) {
   DVLOG(1) << "Enabling an off-thread sync type: " << ModelTypeToString(type);
@@ -198,13 +192,8 @@ void ModelTypeRegistry::ConnectSyncTypeToWorker(
   // Initialize Worker -> Proxy communication channel.
   scoped_ptr<ModelTypeSyncProxy> proxy(
       new ModelTypeSyncProxyWrapper(proxy_impl, type_task_runner));
-  scoped_ptr<ModelTypeSyncWorkerImpl> worker(
-      new ModelTypeSyncWorkerImpl(type,
-                                  data_type_state,
-                                  saved_pending_updates,
-                                  &cryptographer_provider_,
-                                  nudge_handler_,
-                                  proxy.Pass()));
+  scoped_ptr<ModelTypeSyncWorkerImpl> worker(new ModelTypeSyncWorkerImpl(
+      type, data_type_state, nudge_handler_, proxy.Pass()));
 
   // Initialize Proxy -> Worker communication channel.
   scoped_ptr<ModelTypeSyncWorker> wrapped_worker(
diff --git a/sync/sessions/model_type_registry.h b/sync/sessions/model_type_registry.h
index 2399f22..e18ac9c 100644
--- a/sync/sessions/model_type_registry.h
+++ b/sync/sessions/model_type_registry.h
@@ -12,11 +12,9 @@
 #include "base/memory/scoped_vector.h"
 #include "base/memory/weak_ptr.h"
 #include "sync/base/sync_export.h"
-#include "sync/engine/directory_cryptographer_provider.h"
 #include "sync/engine/nudge_handler.h"
 #include "sync/internal_api/public/base/model_type.h"
 #include "sync/internal_api/public/engine/model_safe_worker.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
 #include "sync/internal_api/public/sessions/type_debug_info_observer.h"
 #include "sync/internal_api/public/sync_context.h"
 
@@ -33,6 +31,7 @@ class DirectoryTypeDebugInfoEmitter;
 class ModelTypeSyncWorkerImpl;
 class ModelTypeSyncProxyImpl;
 class UpdateHandler;
+struct DataTypeState;
 
 typedef std::map<ModelType, UpdateHandler*> UpdateHandlerMap;
 typedef std::map<ModelType, CommitContributor*> CommitContributorMap;
@@ -58,7 +57,6 @@ class SYNC_EXPORT_PRIVATE ModelTypeRegistry : public SyncContext {
   virtual void ConnectSyncTypeToWorker(
       syncer::ModelType type,
       const DataTypeState& data_type_state,
-      const syncer::UpdateResponseDataList& saved_pending_updates,
       const scoped_refptr<base::SequencedTaskRunner>& type_task_runner,
       const base::WeakPtr<ModelTypeSyncProxyImpl>& proxy) OVERRIDE;
 
@@ -114,9 +112,6 @@ class SYNC_EXPORT_PRIVATE ModelTypeRegistry : public SyncContext {
   // The directory.  Not owned.
   syncable::Directory* directory_;
 
-  // Provides access to the Directory's cryptographer.
-  DirectoryCryptographerProvider cryptographer_provider_;
-
   // The NudgeHandler.  Not owned.
   NudgeHandler* nudge_handler_;
 
diff --git a/sync/sessions/model_type_registry_unittest.cc b/sync/sessions/model_type_registry_unittest.cc
index 96d6294..b1f1a49 100644
--- a/sync/sessions/model_type_registry_unittest.cc
+++ b/sync/sessions/model_type_registry_unittest.cc
@@ -154,7 +154,6 @@ TEST_F(ModelTypeRegistryTest, NonBlockingTypes) {
 
   registry()->ConnectSyncTypeToWorker(syncer::THEMES,
                                       MakeInitialDataTypeState(THEMES),
-                                      UpdateResponseDataList(),
                                       task_runner,
                                       themes_sync_proxy.AsWeakPtrForUI());
   EXPECT_TRUE(registry()->GetEnabledTypes().Equals(
@@ -162,7 +161,6 @@ TEST_F(ModelTypeRegistryTest, NonBlockingTypes) {
 
   registry()->ConnectSyncTypeToWorker(syncer::SESSIONS,
                                       MakeInitialDataTypeState(SESSIONS),
-                                      UpdateResponseDataList(),
                                       task_runner,
                                       sessions_sync_proxy.AsWeakPtrForUI());
   EXPECT_TRUE(registry()->GetEnabledTypes().Equals(
@@ -194,7 +192,6 @@ TEST_F(ModelTypeRegistryTest, NonBlockingTypesWithDirectoryTypes) {
   // Add the themes non-blocking type.
   registry()->ConnectSyncTypeToWorker(syncer::THEMES,
                                       MakeInitialDataTypeState(THEMES),
-                                      UpdateResponseDataList(),
                                       task_runner,
                                       themes_sync_proxy.AsWeakPtrForUI());
   current_types.Put(syncer::THEMES);
@@ -208,7 +205,6 @@ TEST_F(ModelTypeRegistryTest, NonBlockingTypesWithDirectoryTypes) {
   // Add sessions non-blocking type.
   registry()->ConnectSyncTypeToWorker(syncer::SESSIONS,
                                       MakeInitialDataTypeState(SESSIONS),
-                                      UpdateResponseDataList(),
                                       task_runner,
                                       sessions_sync_proxy.AsWeakPtrForUI());
   current_types.Put(syncer::SESSIONS);
@@ -239,12 +235,10 @@ TEST_F(ModelTypeRegistryTest, DeletionOrdering) {
 
   registry()->ConnectSyncTypeToWorker(syncer::THEMES,
                                       MakeInitialDataTypeState(THEMES),
-                                      UpdateResponseDataList(),
                                       task_runner,
                                       themes_sync_proxy->AsWeakPtrForUI());
   registry()->ConnectSyncTypeToWorker(syncer::SESSIONS,
                                       MakeInitialDataTypeState(SESSIONS),
-                                      UpdateResponseDataList(),
                                       task_runner,
                                       sessions_sync_proxy->AsWeakPtrForUI());
   EXPECT_TRUE(registry()->GetEnabledTypes().Equals(
diff --git a/sync/test/engine/injectable_sync_context_proxy.cc b/sync/test/engine/injectable_sync_context_proxy.cc
index 310a198..27de880 100644
--- a/sync/test/engine/injectable_sync_context_proxy.cc
+++ b/sync/test/engine/injectable_sync_context_proxy.cc
@@ -20,7 +20,6 @@ InjectableSyncContextProxy::~InjectableSyncContextProxy() {
 void InjectableSyncContextProxy::ConnectTypeToSync(
     syncer::ModelType type,
     const DataTypeState& data_type_state,
-    const UpdateResponseDataList& response_list,
     const base::WeakPtr<syncer::ModelTypeSyncProxyImpl>& type_sync_proxy) {
   // This class is allowed to participate in only one connection.
   DCHECK(!is_worker_connected_);
diff --git a/sync/test/engine/injectable_sync_context_proxy.h b/sync/test/engine/injectable_sync_context_proxy.h
index a6303f1..7c9f48d 100644
--- a/sync/test/engine/injectable_sync_context_proxy.h
+++ b/sync/test/engine/injectable_sync_context_proxy.h
@@ -6,7 +6,6 @@
 #define SYNC_TEST_ENGINE_INJECTABLE_SYNC_CONTEXT_PROXY_H_
 
 #include "sync/internal_api/public/base/model_type.h"
-#include "sync/internal_api/public/non_blocking_sync_common.h"
 #include "sync/internal_api/public/sync_context_proxy.h"
 
 namespace syncer {
@@ -25,7 +24,6 @@ class InjectableSyncContextProxy : public syncer::SyncContextProxy {
   virtual void ConnectTypeToSync(
       syncer::ModelType type,
       const DataTypeState& data_type_state,
-      const UpdateResponseDataList& pending_updates,
       const base::WeakPtr<syncer::ModelTypeSyncProxyImpl>& type_sync_proxy)
       OVERRIDE;
   virtual void Disconnect(syncer::ModelType type) OVERRIDE;
diff --git a/sync/test/engine/mock_model_type_sync_proxy.cc b/sync/test/engine/mock_model_type_sync_proxy.cc
index 423a37a..56f53fb1 100644
--- a/sync/test/engine/mock_model_type_sync_proxy.cc
+++ b/sync/test/engine/mock_model_type_sync_proxy.cc
@@ -29,13 +29,11 @@ void MockModelTypeSyncProxy::OnCommitCompleted(
 
 void MockModelTypeSyncProxy::OnUpdateReceived(
     const DataTypeState& type_state,
-    const UpdateResponseDataList& response_list,
-    const UpdateResponseDataList& pending_updates) {
+    const UpdateResponseDataList& response_list) {
   base::Closure task = base::Bind(&MockModelTypeSyncProxy::OnUpdateReceivedImpl,
                                   base::Unretained(this),
                                   type_state,
-                                  response_list,
-                                  pending_updates);
+                                  response_list);
   pending_tasks_.push_back(task);
   if (is_synchronous_)
     RunQueuedTasks();
@@ -113,12 +111,6 @@ UpdateResponseDataList MockModelTypeSyncProxy::GetNthUpdateResponse(
   return received_update_responses_[n];
 }
 
-UpdateResponseDataList MockModelTypeSyncProxy::GetNthPendingUpdates(
-    size_t n) const {
-  DCHECK_LT(n, GetNumUpdateResponses());
-  return received_pending_updates_[n];
-}
-
 DataTypeState MockModelTypeSyncProxy::GetNthTypeStateReceivedInUpdateResponse(
     size_t n) const {
   DCHECK_LT(n, GetNumUpdateResponses());
@@ -189,10 +181,8 @@ void MockModelTypeSyncProxy::OnCommitCompletedImpl(
 
 void MockModelTypeSyncProxy::OnUpdateReceivedImpl(
     const DataTypeState& type_state,
-    const UpdateResponseDataList& response_list,
-    const UpdateResponseDataList& pending_updates) {
+    const UpdateResponseDataList& response_list) {
   received_update_responses_.push_back(response_list);
-  received_pending_updates_.push_back(pending_updates);
   type_states_received_on_update_.push_back(type_state);
   for (UpdateResponseDataList::const_iterator it = response_list.begin();
        it != response_list.end();
diff --git a/sync/test/engine/mock_model_type_sync_proxy.h b/sync/test/engine/mock_model_type_sync_proxy.h
index 140904b..271b59f 100644
--- a/sync/test/engine/mock_model_type_sync_proxy.h
+++ b/sync/test/engine/mock_model_type_sync_proxy.h
@@ -36,8 +36,7 @@ class MockModelTypeSyncProxy : public ModelTypeSyncProxy {
       const CommitResponseDataList& response_list) OVERRIDE;
   virtual void OnUpdateReceived(
       const DataTypeState& type_state,
-      const UpdateResponseDataList& response_list,
-      const UpdateResponseDataList& pending_updates) OVERRIDE;
+      const UpdateResponseDataList& response_list) OVERRIDE;
 
   // By default, this object behaves as if all messages are processed
   // immediately.  Sometimes it is useful to defer work until later, as might
@@ -66,7 +65,6 @@ class MockModelTypeSyncProxy : public ModelTypeSyncProxy {
   // Does not includes repsonses that are in pending tasks.
   size_t GetNumUpdateResponses() const;
   UpdateResponseDataList GetNthUpdateResponse(size_t n) const;
-  UpdateResponseDataList GetNthPendingUpdates(size_t n) const;
   DataTypeState GetNthTypeStateReceivedInUpdateResponse(size_t n) const;
 
   // Getters to access the log of received commit responses.
@@ -95,8 +93,7 @@ class MockModelTypeSyncProxy : public ModelTypeSyncProxy {
   //
   // Implemented as an Impl method so we can defer its execution in some cases.
   void OnUpdateReceivedImpl(const DataTypeState& type_state,
-                            const UpdateResponseDataList& response_list,
-                            const UpdateResponseDataList& pending_updates);
+                            const UpdateResponseDataList& response_list);
 
   // Getter and setter for per-item sequence number tracking.
   int64 GetCurrentSequenceNumber(const std::string& tag_hash) const;
@@ -119,7 +116,6 @@ class MockModelTypeSyncProxy : public ModelTypeSyncProxy {
   // A log of messages received by this object.
   std::vector<CommitResponseDataList> received_commit_responses_;
   std::vector<UpdateResponseDataList> received_update_responses_;
-  std::vector<UpdateResponseDataList> received_pending_updates_;
   std::vector<DataTypeState> type_states_received_on_update_;
   std::vector<DataTypeState> type_states_received_on_commit_;
 
diff --git a/sync/test/engine/mock_model_type_sync_worker.cc b/sync/test/engine/mock_model_type_sync_worker.cc
index 8b6b523..9c90232 100644
--- a/sync/test/engine/mock_model_type_sync_worker.cc
+++ b/sync/test/engine/mock_model_type_sync_worker.cc
@@ -94,8 +94,6 @@ UpdateResponseData MockModelTypeSyncWorker::UpdateFromServer(
   data.mtime = data.ctime + base::TimeDelta::FromSeconds(version);
   data.non_unique_name = specifics.preference().name();
 
-  data.encryption_key_name = server_encryption_key_name_;
-
   return data;
 }
 
@@ -120,8 +118,6 @@ UpdateResponseData MockModelTypeSyncWorker::TombstoneFromServer(
   data.mtime = data.ctime + base::TimeDelta::FromSeconds(version);
   data.non_unique_name = "Name Non Unique";
 
-  data.encryption_key_name = server_encryption_key_name_;
-
   return data;
 }
 
@@ -153,11 +149,6 @@ CommitResponseData MockModelTypeSyncWorker::SuccessfulCommitResponse(
   return response_data;
 }
 
-void MockModelTypeSyncWorker::SetServerEncryptionKey(
-    const std::string& key_name) {
-  server_encryption_key_name_ = key_name;
-}
-
 std::string MockModelTypeSyncWorker::GenerateId(const std::string& tag_hash) {
   return "FakeId:" + tag_hash;
 }
diff --git a/sync/test/engine/mock_model_type_sync_worker.h b/sync/test/engine/mock_model_type_sync_worker.h
index b33e548..498e9ee 100644
--- a/sync/test/engine/mock_model_type_sync_worker.h
+++ b/sync/test/engine/mock_model_type_sync_worker.h
@@ -57,11 +57,6 @@ class MockModelTypeSyncWorker : public ModelTypeSyncWorker {
   CommitResponseData SuccessfulCommitResponse(
       const CommitRequestData& request_data);
 
-  // Sets the encryption key name used for updates from the server.
-  // (ie. the key other clients are using to encrypt their commits.)
-  // The default value is an empty string, which indicates no encryption.
-  void SetServerEncryptionKey(const std::string& key_name);
-
  private:
   // Generate an ID string.
   static std::string GenerateId(const std::string& tag_hash);
@@ -77,9 +72,6 @@ class MockModelTypeSyncWorker : public ModelTypeSyncWorker {
   // This is an essential part of the mocked server state.
   std::map<const std::string, int64> server_versions_;
 
-  // Name of the encryption key in use on other clients.
-  std::string server_encryption_key_name_;
-
   DISALLOW_COPY_AND_ASSIGN(MockModelTypeSyncWorker);
 };
 
diff --git a/sync/util/cryptographer.cc b/sync/util/cryptographer.cc
index cb155b5..29f3781 100644
--- a/sync/util/cryptographer.cc
+++ b/sync/util/cryptographer.cc
@@ -251,7 +251,7 @@ bool Cryptographer::DecryptPendingKeys(const KeyParams& params) {
 
 bool Cryptographer::GetBootstrapToken(std::string* token) const {
   DCHECK(token);
-  std::string unencrypted_token = GetDefaultNigoriKeyData();
+  std::string unencrypted_token = GetDefaultNigoriKey();
   if (unencrypted_token.empty())
     return false;
 
@@ -324,11 +324,7 @@ bool Cryptographer::KeybagIsStale(
   return false;
 }
 
-std::string Cryptographer::GetDefaultNigoriKeyName() const {
-  return default_nigori_name_;
-}
-
-std::string Cryptographer::GetDefaultNigoriKeyData() const {
+std::string Cryptographer::GetDefaultNigoriKey() const {
   if (!is_initialized())
     return std::string();
   NigoriMap::const_iterator iter = nigoris_.find(default_nigori_name_);
diff --git a/sync/util/cryptographer.h b/sync/util/cryptographer.h
index 9876f83..2dfdedc 100644
--- a/sync/util/cryptographer.h
+++ b/sync/util/cryptographer.h
@@ -176,12 +176,9 @@ class SYNC_EXPORT Cryptographer {
   // and/or has a different default key.
   bool KeybagIsStale(const sync_pb::EncryptedData& keybag) const;
 
-  // Returns the name of the Nigori key currently used for encryption.
-  std::string GetDefaultNigoriKeyName() const;
-
   // Returns a serialized sync_pb::NigoriKey version of current default
   // encryption key.
-  std::string GetDefaultNigoriKeyData() const;
+  std::string GetDefaultNigoriKey() const;
 
   // Generates a new Nigori from |serialized_nigori_key|, and if successful
   // installs the new nigori as the default key.