Indexed DB: Simplify cursor iteration logic

content/browser/indexed_db/indexed_db_backing_store.h

Index: content/browser/indexed_db/indexed_db_backing_store.h
diff --git a/content/browser/indexed_db/indexed_db_backing_store.h b/content/browser/indexed_db/indexed_db_backing_store.h
index 7b11a600f9cd99c8fda48b9119aef2b95afa52b3..89cfae048eb7407abf490f5e90bac898040f336f 100644
--- a/content/browser/indexed_db/indexed_db_backing_store.h
+++ b/content/browser/indexed_db/indexed_db_backing_store.h
@@ -338,6 +338,19 @@ class CONTENT_EXPORT IndexedDBBackingStore
     IndexedDBBackingStore::RecordIdentifier record_identifier_;
 
    private:
+    // For cursors with direction Next or NextNoDuplicate.
+    bool ContinueNext(const IndexedDBKey* key,
+                      const IndexedDBKey* primary_key,
+                      IteratorState state,
+                      leveldb::Status*);
+    // For cursors with direction Prev or PrevNoDuplicate.
+    // The PrevNoDuplicate case has additional complexity of not
+    // being symmetric with PrevNoDuplicate.

[jsbell, 2015/06/09 15:47:32]

I meant this to say "NextNoDuplicate"

[jsbell, 2015/06/10 17:51:58]

Done.

+    bool ContinuePrevious(const IndexedDBKey* key,
+                          const IndexedDBKey* primary_key,
+                          IteratorState state,
+                          leveldb::Status*);
+
     DISALLOW_COPY_AND_ASSIGN(Cursor);
   };