void Put(TabId tab_id, const SkBitmap& bitmap, float thumbnail_scale);
void Remove(TabId tab_id);
- Thumbnail* Get(TabId tab_id, bool force_disk_read);
+ Thumbnail* Get(TabId tab_id, bool force_disk_read, bool allow_approximation);
void RemoveFromDiskAtAndAboveId(TabId min_id);
void InvalidateThumbnailIfChanged(TabId tab_id, const GURL& url);