This is the implementation of the primary and secondary blob journals for

content/browser/indexed_db/indexed_db_leveldb_coding.cc

Index: content/browser/indexed_db/indexed_db_leveldb_coding.cc
diff --git a/content/browser/indexed_db/indexed_db_leveldb_coding.cc b/content/browser/indexed_db/indexed_db_leveldb_coding.cc
index 44556833f69543eb6ee523724a9c01e9dc8e4f44..2de9b6d585db798e7ecc3fee710bae07de6e5bc0 100644
--- a/content/browser/indexed_db/indexed_db_leveldb_coding.cc
+++ b/content/browser/indexed_db/indexed_db_leveldb_coding.cc
@@ -375,6 +375,14 @@ void EncodeIDBKeyPath(const IndexedDBKeyPath& value, std::string* into) {
   }
 }
 
+void EncodeBlobJournal(const BlobJournalType& journal, std::string* into) {
+  BlobJournalType::const_iterator iter;
+  for (iter = journal.begin(); iter != journal.end(); ++iter) {

[cmumford, 2014/04/30 21:29:30]

If the journal is empty (which may not be possible?) is it OK to leave "into"
untouched?

[ericu, 2014/04/30 22:16:10]

Yes.  The convention in this file is that all EncodeXXX functions append, rather
than replacing.

+    EncodeVarInt(iter->first, into);
+    EncodeVarInt(iter->second, into);
+  }
+}
+
 bool DecodeByte(StringPiece* slice, unsigned char* value) {
   if (slice->empty())
     return false;
@@ -607,6 +615,27 @@ bool DecodeIDBKeyPath(StringPiece* slice, IndexedDBKeyPath* value) {
   return false;
 }
 
+bool DecodeBlobJournal(StringPiece* slice, BlobJournalType* journal) {
+  BlobJournalType output;

[cmumford, 2014/04/30 21:29:30]

Should an empty slice be considered an error?

[ericu, 2014/04/30 22:16:10]

No, that's an empty journal.

+  while (!slice->empty()) {
+    int64 database_id = -1;
+    int64 blob_key = -1;
+    if (!DecodeVarInt(slice, &database_id))
+      return false;
+    if (!KeyPrefix::IsValidDatabaseId(database_id))
+      return false;
+    if (!DecodeVarInt(slice, &blob_key))
+      return false;
+    if (!DatabaseMetaDataKey::IsValidBlobKey(blob_key) &&
+        (blob_key != DatabaseMetaDataKey::kAllBlobsKey)) {
+      return false;
+    }
+    output.push_back(std::make_pair(database_id, blob_key));
+  }
+  journal->swap(output);
+  return true;
+}
+
 bool ConsumeEncodedIDBKey(StringPiece* slice) {
   unsigned char type = (*slice)[0];
   slice->remove_prefix(1);