Add information about sync session and other useful data to about:sync.

chrome/browser/sync/sessions/status_controller.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // StatusController handles all counter and status related number crunching and
 // state tracking on behalf of a SyncSession.  It 'controls' the model data
 // defined in session_state.h.  The most important feature of StatusController
 // is the ScopedModelSafetyRestriction. When one of these is active, the
 // underlying data set exposed via accessors is swapped out to the appropriate
 // set for the restricted ModelSafeGroup behind the scenes.  For example, if
@@ skipping 197 matching lines @@
   void reset_num_conflicting_commits();
   void set_num_consecutive_transient_error_commits(int value);
   void increment_num_consecutive_transient_error_commits_by(int value);
   void set_num_consecutive_errors(int value);
   void increment_num_consecutive_errors();
   void increment_num_consecutive_errors_by(int value);
   void set_num_server_changes_remaining(int64 changes_remaining);
   void set_invalid_store(bool invalid_store);
   void set_syncer_stuck(bool syncer_stuck);
   void set_syncing(bool syncing);
+  void set_throttled();
   void set_num_successful_bookmark_commits(int value);
   void increment_num_successful_commits();
   void increment_num_successful_bookmark_commits();
   void increment_num_updates_downloaded_by(int value);
   void increment_num_tombstone_updates_downloaded_by(int value);
   void set_types_needing_local_migration(const syncable::ModelTypeSet& types);
   void set_unsynced_handles(const std::vector<int64>& unsynced_handles);
   void increment_num_local_overwrites();
   void increment_num_server_overwrites();
 
@@ skipping 51 matching lines @@
   }
  private:
   StatusController* status_;
   DISALLOW_COPY_AND_ASSIGN(ScopedModelSafeGroupRestriction);
 };
 
 }
 }
 
 #endif  // CHROME_BROWSER_SYNC_SESSIONS_STATUS_CONTROLLER_H_