[Sync] Add check to help debug CreateOrUpdateSyncNode errors.

We check if we succeed in decrypting data, but fail in parsing the string into
a protobuf.

BUG=123223
TEST=


Review URL: https://chromiumcodereview.appspot.com/10387089

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@136695 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 10 insertions, 2 deletions

diff --git a/sync/internal_api/base_node.cc b/sync/internal_api/base_node.cc
index 552ee71..99f1614 100644
--- a/sync/internal_api/base_node.cc
+++ b/sync/internal_api/base_node.cc
@@ -118,10 +118,18 @@ bool BaseNode::DecryptIfNecessary() {
   const sync_pb::EncryptedData& encrypted = specifics.encrypted();
   std::string plaintext_data = GetTransaction()->GetCryptographer()->
       DecryptToString(encrypted);
-  if (plaintext_data.length() == 0 ||
-      !unencrypted_data_.ParseFromString(plaintext_data)) {
+  if (plaintext_data.length() == 0) {
     LOG(ERROR) << "Failed to decrypt encrypted node of type " <<
       syncable::ModelTypeToString(GetModelType()) << ".";
+    // Debugging for crbug.com/123223. We failed to decrypt the data, which
+    // means we applied an update without having the key or lost the key at a
+    // later point.
+    CHECK(false);
+    return false;
+  } else if (!unencrypted_data_.ParseFromString(plaintext_data)) {
+    // Debugging for crbug.com/123223. We should never succeed in decrypting
+    // but fail to parse into a protobuf.
+    CHECK(false);
     return false;
   }
   DVLOG(2) << "Decrypted specifics of type "