[Sync] USS: Ignore encryption changes during conflict resolution 1/2

sync/internal_api/processor_entity_tracker.cc

Index: sync/internal_api/processor_entity_tracker.cc
diff --git a/sync/internal_api/processor_entity_tracker.cc b/sync/internal_api/processor_entity_tracker.cc
index 8e3e149ad5ca869a1b76e028a35be87843787662..6aa5677c57306722aa32c53fec5aa03f9132cb33 100644
--- a/sync/internal_api/processor_entity_tracker.cc
+++ b/sync/internal_api/processor_entity_tracker.cc
@@ -19,6 +19,7 @@ namespace {
 
 void HashSpecifics(const sync_pb::EntitySpecifics& specifics,
                    std::string* hash) {
+  DCHECK_GT(specifics.ByteSize(), 0);
   base::Base64Encode(base::SHA1HashString(specifics.SerializeAsString()), hash);
 }
 
@@ -80,19 +81,21 @@ bool ProcessorEntityTracker::HasCommitData() const {
   return !commit_data_->client_tag_hash.empty();
 }
 
-bool ProcessorEntityTracker::MatchesSpecificsHash(
-    const sync_pb::EntitySpecifics& specifics) const {
-  DCHECK_GT(specifics.ByteSize(), 0);
-  std::string hash;
-  HashSpecifics(specifics, &hash);
-  return hash == metadata_.specifics_hash();
-}
-
 bool ProcessorEntityTracker::MatchesData(const EntityData& data) const {
-  return (data.is_deleted() && metadata_.is_deleted()) ||
+  return metadata_.is_deleted() ? data.is_deleted() :
          MatchesSpecificsHash(data.specifics);
 }
 
+bool ProcessorEntityTracker::MatchesBaseData(const EntityData& data) const {
+  DCHECK(IsUnsynced());
+  if (data.is_deleted() || metadata_.base_specifics_hash().empty()) {
+    return false;
+  }
+  std::string hash;
+  HashSpecifics(data.specifics, &hash);
+  return hash == metadata_.base_specifics_hash();
+}
+
 bool ProcessorEntityTracker::IsUnsynced() const {
   return metadata_.sequence_number() > metadata_.acked_sequence_number();
 }
@@ -149,11 +152,11 @@ void ProcessorEntityTracker::MakeLocalChange(std::unique_ptr<EntityData> data) {
     data->modification_time = base::Time::Now();
   }
 
+  IncrementSequenceNumber();
+  UpdateSpecificsHash(data->specifics);
   metadata_.set_modification_time(
       syncer::TimeToProtoTime(data->modification_time));
   metadata_.set_is_deleted(false);
-  IncrementSequenceNumber();
-  UpdateSpecificsHash(data->specifics);
 
   data->id = metadata_.server_id();
   data->creation_time = syncer::ProtoTimeToTime(metadata_.creation_time());
@@ -187,23 +190,27 @@ void ProcessorEntityTracker::InitializeCommitRequestData(
 
   request->sequence_number = metadata_.sequence_number();
   request->base_version = metadata_.server_version();
+  request->specifics_hash = metadata_.specifics_hash();
   commit_requested_sequence_number_ = metadata_.sequence_number();
 }
 
 void ProcessorEntityTracker::ReceiveCommitResponse(
-    const std::string& id,
-    int64_t sequence_number,
-    int64_t response_version) {
-  DCHECK(sequence_number > metadata_.acked_sequence_number());
+    const CommitResponseData& data) {
+  DCHECK_EQ(metadata_.client_tag_hash(), data.client_tag_hash);
+  DCHECK_GT(data.sequence_number, metadata_.acked_sequence_number());
+  DCHECK_GT(data.response_version, metadata_.server_version());
 
   // The server can assign us a new ID in a commit response.
-  metadata_.set_server_id(id);
-  metadata_.set_acked_sequence_number(sequence_number);
-  metadata_.set_server_version(response_version);
+  metadata_.set_server_id(data.id);
+  metadata_.set_acked_sequence_number(data.sequence_number);
+  metadata_.set_server_version(data.response_version);
   if (!IsUnsynced()) {
     // Clear pending commit data if there hasn't been another commit request
     // since the one that is currently getting acked.
     commit_data_.reset();
+    metadata_.clear_base_specifics_hash();
+  } else {
+    metadata_.set_base_specifics_hash(data.specifics_hash);
   }
 }
 
@@ -215,10 +222,21 @@ void ProcessorEntityTracker::ClearTransientSyncState() {
 
 void ProcessorEntityTracker::IncrementSequenceNumber() {
   DCHECK(metadata_.has_sequence_number());
+  if (!IsUnsynced()) {
+    // Update the base specifics hash if this entity wasn't already out of sync.
+    metadata_.set_base_specifics_hash(metadata_.specifics_hash());
+  }
   metadata_.set_sequence_number(metadata_.sequence_number() + 1);
 }
 
-// Update hash string for EntitySpecifics.
+bool ProcessorEntityTracker::MatchesSpecificsHash(
+    const sync_pb::EntitySpecifics& specifics) const {
+  DCHECK(!metadata_.is_deleted());
+  std::string hash;
+  HashSpecifics(specifics, &hash);
+  return hash == metadata_.specifics_hash();
+}
+
 void ProcessorEntityTracker::UpdateSpecificsHash(
     const sync_pb::EntitySpecifics& specifics) {
   if (specifics.ByteSize() > 0) {