[Suggestions] Remove support for a Control logging group.

chrome/browser/android/most_visited_sites.h

Index: chrome/browser/android/most_visited_sites.h
diff --git a/chrome/browser/android/most_visited_sites.h b/chrome/browser/android/most_visited_sites.h
index 6e5a7f52a5663b1eb2fca8aab909c821c18b8a42..ab4b419d6e6768d8edf2e1574140da5dd65e919c 100644
--- a/chrome/browser/android/most_visited_sites.h
+++ b/chrome/browser/android/most_visited_sites.h
@@ -108,9 +108,6 @@ class MostVisitedSites : public ProfileSyncServiceObserver,
   // The maximum number of most visited sites to return.
   int num_sites_;
 
-  // Whether the user is in a control group for the purposes of logging.
-  bool is_control_group_;
-
   // Keeps track of whether the initial NTP load has been done.
   bool initial_load_done_;