| Index: chrome/browser/ui/browser_commands.cc | 
| diff --git a/chrome/browser/ui/browser_commands.cc b/chrome/browser/ui/browser_commands.cc | 
| index fd1c0adf77e95dedc17aede0ec10c19c3cf927e7..c1d4bba4c7700dc061aabf0744ce9720097ab936 100644 | 
| --- a/chrome/browser/ui/browser_commands.cc | 
| +++ b/chrome/browser/ui/browser_commands.cc | 
| @@ -1008,7 +1008,8 @@ void ViewSource(Browser* browser, | 
| // Note that Clone does not copy the pending or transient entries, so the | 
| // active entry in view_source_contents will be the last committed entry. | 
| WebContents* view_source_contents = contents->Clone(); | 
| -  view_source_contents->GetController().PruneAllButActive(); | 
| +  DCHECK(view_source_contents->GetController().CanPruneAllButVisible()); | 
| +  view_source_contents->GetController().PruneAllButVisible(); | 
| NavigationEntry* active_entry = | 
| view_source_contents->GetController().GetActiveEntry(); | 
| if (!active_entry) | 
|  |