Improve the about/discards UI, allowing each tab to be individually closed.

chrome/browser/memory/tab_stats.h

Index: chrome/browser/memory/tab_stats.h
diff --git a/chrome/browser/memory/tab_stats.h b/chrome/browser/memory/tab_stats.h
index 690f6a8c420c29680001ca831316a380a72beff2..aa49e50e5b766531f778180a22de919b3fbea3d3 100644
--- a/chrome/browser/memory/tab_stats.h
+++ b/chrome/browser/memory/tab_stats.h
@@ -26,6 +26,9 @@ struct TabStats {
   base::ProcessHandle renderer_handle;
   int child_process_host_id;
   base::string16 title;
+#if defined(OS_CHROMEOS)
+  int oom_score;
+#endif
   int64 tab_contents_id;  // Unique ID per WebContents.
 };