Track fraction of visits to top URLs.

chrome/browser/history/history_backend.h

Index: chrome/browser/history/history_backend.h
diff --git a/chrome/browser/history/history_backend.h b/chrome/browser/history/history_backend.h
index 2aff6599cf09598c4cc10bebc5b6fbb960bd1304..2827fc4772da0a9657d357d80971d295e8bb17c7 100644
--- a/chrome/browser/history/history_backend.h
+++ b/chrome/browser/history/history_backend.h
@@ -904,6 +904,12 @@ class HistoryBackend : public base::RefCountedThreadSafe<HistoryBackend>,
 #if defined(OS_ANDROID)
   // Used to provide the Android ContentProvider APIs.
   scoped_ptr<AndroidProviderBackend> android_provider_backend_;
+
+  // Used to provide UMA on the number of page visits that are to the most
+  // visited URLs. This is here because the backend both has access to this
+  // information and is notified of page visits. The top sites service should
+  // be used instead whenever possible.
+  MostVisitedURLList most_visited_urls_;

[jar (doing other things), 2013/06/17 22:58:14]

nit: I went to see what type this was... and noticed it was defined twice in
chrome/browser/history/history_types.h.  Perhaps you could also delete the
redundant declaration.

[bengr, 2013/06/17 23:46:59]

Done.

 #endif
 
   // Used to manage syncing of the typed urls datatype. This will be NULL