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

chrome/browser/sync/engine/all_status.cc

 // 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.
 
 #include "chrome/browser/sync/engine/all_status.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/port.h"
@@ skipping 61 matching lines @@
   // counter preserve its value across sessions.  http://crbug.com/26339
   if (event.what_happened == SyncEngineEvent::SYNC_CYCLE_ENDED) {
     status.updates_received +=
         snapshot->syncer_status.num_updates_downloaded_total;
     status.tombstone_updates_received +=
         snapshot->syncer_status.num_tombstone_updates_downloaded_total;
     status.num_local_overwrites_total +=
         snapshot->syncer_status.num_local_overwrites;
     status.num_server_overwrites_total +=
         snapshot->syncer_status.num_server_overwrites;
+    if (snapshot->syncer_status.num_updates_downloaded_total == 0) {
+      ++status.empty_get_updates;
+    } else {
+      ++status.nonempty_get_updates;
+    }
+    if (snapshot->syncer_status.num_successful_commits == 0 &&
+        snapshot->syncer_status.num_updates_downloaded_total == 0) {
+      ++status.useless_sync_cycles;
+    } else {
+      ++status.useful_sync_cycles;
+    }
   }
   return status;
 }
 
 void AllStatus::CalcStatusChanges() {
   const bool unsynced_changes = status_.unsynced_count > 0;
   const bool online = status_.authenticated &&
     status_.server_reachable && status_.server_up && !status_.server_broken;
   if (online) {
     if (status_.syncer_stuck)
@@ skipping 66 matching lines @@
     : allstatus_(allstatus) {
   allstatus->mutex_.Acquire();
 }
 
 ScopedStatusLock::~ScopedStatusLock() {
   allstatus_->CalcStatusChanges();
   allstatus_->mutex_.Release();
 }
 
 }  // namespace browser_sync