Use a two-part data format version in IndexedDB metadata.

content/browser/indexed_db/indexed_db_factory_impl.cc

Index: content/browser/indexed_db/indexed_db_factory_impl.cc
diff --git a/content/browser/indexed_db/indexed_db_factory_impl.cc b/content/browser/indexed_db/indexed_db_factory_impl.cc
index b8a553642a56f9d7861bae6025756eee0c78b383..9726ec2d9e3defe18aece5959ffe5d67957e6575 100644
--- a/content/browser/indexed_db/indexed_db_factory_impl.cc
+++ b/content/browser/indexed_db/indexed_db_factory_impl.cc
@@ -173,6 +173,7 @@ void IndexedDBFactoryImpl::GetDatabaseNames(
     scoped_refptr<IndexedDBCallbacks> callbacks,
     const Origin& origin,
     const base::FilePath& data_directory,
+    const IndexedDBDataFormatVersion& client_data_format_version,
     scoped_refptr<net::URLRequestContextGetter> request_context_getter) {
   IDB_TRACE("IndexedDBFactoryImpl::GetDatabaseNames");
   // TODO(dgrogan): Plumb data_loss back to script eventually?
@@ -181,8 +182,8 @@ void IndexedDBFactoryImpl::GetDatabaseNames(
   leveldb::Status s;
   // TODO(cmumford): Handle this error
   scoped_refptr<IndexedDBBackingStore> backing_store =
-      OpenBackingStore(origin, data_directory, request_context_getter,
-                       &data_loss_info, &disk_full, &s);
+      OpenBackingStore(origin, data_directory, client_data_format_version,
+                       request_context_getter, &data_loss_info, &disk_full, &s);
   if (!backing_store.get()) {
     callbacks->OnError(
         IndexedDBDatabaseError(blink::WebIDBDatabaseExceptionUnknownError,
@@ -214,6 +215,7 @@ void IndexedDBFactoryImpl::DeleteDatabase(
     scoped_refptr<IndexedDBCallbacks> callbacks,
     const Origin& origin,
     const base::FilePath& data_directory,
+    const IndexedDBDataFormatVersion& client_data_format_version,
     bool force_close) {
   IDB_TRACE("IndexedDBFactoryImpl::DeleteDatabase");
   IndexedDBDatabase::Identifier unique_identifier(origin, name);
@@ -230,8 +232,8 @@ void IndexedDBFactoryImpl::DeleteDatabase(
   bool disk_full = false;
   leveldb::Status s;
   scoped_refptr<IndexedDBBackingStore> backing_store =
-      OpenBackingStore(origin, data_directory, request_context_getter,
-                       &data_loss_info, &disk_full, &s);
+      OpenBackingStore(origin, data_directory, client_data_format_version,
+                       request_context_getter, &data_loss_info, &disk_full, &s);
   if (!backing_store.get()) {
     IndexedDBDatabaseError error(blink::WebIDBDatabaseExceptionUnknownError,
                                  ASCIIToUTF16(
@@ -352,19 +354,21 @@ scoped_refptr<IndexedDBBackingStore>
 IndexedDBFactoryImpl::OpenBackingStoreHelper(
     const Origin& origin,
     const base::FilePath& data_directory,
+    const IndexedDBDataFormatVersion& data_format_version,
     scoped_refptr<net::URLRequestContextGetter> request_context_getter,
     IndexedDBDataLossInfo* data_loss_info,
     bool* disk_full,
     bool first_time,
     leveldb::Status* status) {
   return IndexedDBBackingStore::Open(
-      this, origin, data_directory, request_context_getter, data_loss_info,
-      disk_full, context_->TaskRunner(), first_time, status);
+      this, origin, data_directory, data_format_version, request_context_getter,
+      data_loss_info, disk_full, context_->TaskRunner(), first_time, status);
 }
 
 scoped_refptr<IndexedDBBackingStore> IndexedDBFactoryImpl::OpenBackingStore(
     const Origin& origin,
     const base::FilePath& data_directory,
+    const IndexedDBDataFormatVersion& data_format_version,
     scoped_refptr<net::URLRequestContextGetter> request_context_getter,
     IndexedDBDataLossInfo* data_loss_info,
     bool* disk_full,
@@ -373,21 +377,26 @@ scoped_refptr<IndexedDBBackingStore> IndexedDBFactoryImpl::OpenBackingStore(
 
   const auto& it2 = backing_store_map_.find(origin);
   if (it2 != backing_store_map_.end()) {
-    it2->second->close_timer()->Stop();
-    return it2->second;
+    scoped_refptr<IndexedDBBackingStore> backing_store = it2->second;
+    if (backing_store->data_format_version() != data_format_version) {
+      LOG(ERROR) << "IndexedDB backing store already open with a different "
+                    "data format version.";
+    }
+    backing_store->close_timer()->Stop();
+    return backing_store;
   }
 
   scoped_refptr<IndexedDBBackingStore> backing_store;
   bool first_time = false;
   if (open_in_memory) {
     backing_store = IndexedDBBackingStore::OpenInMemory(
-        origin, context_->TaskRunner(), status);
+        origin, data_format_version, context_->TaskRunner(), status);
   } else {
     first_time = !backends_opened_since_boot_.count(origin);
 
-    backing_store =
-        OpenBackingStoreHelper(origin, data_directory, request_context_getter,
-                               data_loss_info, disk_full, first_time, status);
+    backing_store = OpenBackingStoreHelper(
+        origin, data_directory, data_format_version, request_context_getter,
+        data_loss_info, disk_full, first_time, status);
   }
 
   if (backing_store.get()) {
@@ -413,7 +422,8 @@ void IndexedDBFactoryImpl::Open(
     std::unique_ptr<IndexedDBPendingConnection> connection,
     scoped_refptr<net::URLRequestContextGetter> request_context_getter,
     const Origin& origin,
-    const base::FilePath& data_directory) {
+    const base::FilePath& data_directory,
+    const IndexedDBDataFormatVersion& client_data_format_version) {
   IDB_TRACE("IndexedDBFactoryImpl::Open");
   scoped_refptr<IndexedDBDatabase> database;
   IndexedDBDatabase::Identifier unique_identifier(origin, name);
@@ -423,9 +433,9 @@ void IndexedDBFactoryImpl::Open(
   bool was_open = (it != database_map_.end());
   if (!was_open) {
     leveldb::Status s;
-    scoped_refptr<IndexedDBBackingStore> backing_store =
-        OpenBackingStore(origin, data_directory, request_context_getter,
-                         &data_loss_info, &disk_full, &s);
+    scoped_refptr<IndexedDBBackingStore> backing_store = OpenBackingStore(
+        origin, data_directory, client_data_format_version,
+        request_context_getter, &data_loss_info, &disk_full, &s);
     if (!backing_store.get()) {
       if (disk_full) {
         connection->callbacks->OnError(IndexedDBDatabaseError(