[IndexedDB] Adding transaction and value support to observers

content/browser/indexed_db/indexed_db_connection.h

Index: content/browser/indexed_db/indexed_db_connection.h
diff --git a/content/browser/indexed_db/indexed_db_connection.h b/content/browser/indexed_db/indexed_db_connection.h
index 20acb7b7244c0ed10041c8a59b955c37bf2c2419..e691195573844d038605e1397fbadfe8e1a3d4dd 100644
--- a/content/browser/indexed_db/indexed_db_connection.h
+++ b/content/browser/indexed_db/indexed_db_connection.h
@@ -77,9 +77,19 @@ class CONTENT_EXPORT IndexedDBConnection {
   // TODO(dmurph): Change that so this doesn't need to ignore unknown ids.
   void RemoveTransaction(int64_t id);
 
+  // Returns a new transaction id for an observer transaction.
+  // Unique per connection.
+  int64_t NewObserverTransactionId();
+
  private:
   const int32_t id_;
 
+  // The renderer-created transactions are in the right 32 bits of the
+  // transaction id, and the observer (browser-created) transactions are in the
+  // left 32 bits.
+  // This keeps track of the left 32 bits. Unsigned for defined overflow.
+  uint32_t next_observer_transaction_id_ = 1;
+
   // The process id of the child process this connection is associated with.
   // Tracked for IndexedDBContextImpl::GetAllOriginsDetails and debugging.
   const int child_process_id_;